# Patent

## Title
Process for total synthesis of pladienolide B and pladienolide D

## Abstract

Process for producing compound of Formula:




wherein P2, P3 and R2 are the same as defined below, characterized by comprising reacting a compound represented by Formula (7):





wherein P3 means a protecting group for hydroxy group; and Het means a 1-phenyl-1H-tetrazol-5-yl group, with a compound represented by Formula (8):





wherein P2 means a protecting group for hydroxy group; and R2 means a phenyl group which may be substituted, in the presence of a base.

## Background
CROSS-REFERENCE
This application is a Divisional of co-pending application Ser. No. 11/580,047, filed on Oct. 13, 2006, for which priority is claimed under 35 U.S.C. §120. application Ser. No. 11/580,047 in turn claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/727,845, filed on Oct. 19, 2005, and Application No. 2005-299228 filed in Japan on Oct. 13, 2005 under 25 U.S.C. §119. The entire contents of all of these previous applications are hereby incorporated by reference.


TECHNICAL FIELD
The present invention relates to a process for total synthesis of pladienolide B and pladienolide D having excellent anti-tumor activity and intermediates in the above-described process.
BACKGROUND ART
Pladienolide B represented by Formula (1′):




and Pladienolide D represented by Formula (2′):





are 12 membered-ring macrolide compounds found by Sakai et al. in a culture of Streptomyces sp. Mer-11107 strain, and are known to have excellent anti-tumor activity (See Patent Document 1).

However, total synthesis of pladienolide B and pladienolide D has not been reported at all till now, and the purification of the above culture has been the only process for acquiring pladienolide B and pladienolide D. In addition, there was a problem that there was limitation in the structural variety of derivatives obtained by chemical conversion from pladienolide B and pladienolide D themselves which were fermentation products. Furthermore, absolute configuration of pladienolide B and pladienolide D has not yet been determined (See Patent Document 1), and the determination thereof has been a problem to be solved. Accordingly, establishment of a process for total synthesis of pladienolide B and pladienolide D has been strongly desired from the viewpoints of (1) supply of pladienolide B and pladienolide D by chemical synthesis, (2) synthesis of various pladienolide derivatives and (3) determination of absolute configuration of pladienolide B and pladienolide D.
In the meantime, although compounds analogous to pladienolide B and pladienolide D in structure were disclosed in Patent Documents 1 to 5, total synthesis of these compounds was not disclosed in any of the documents.
[Patent Document 1] WO02/60890 pamphlet
[Patent Document 2] JP-A-04-352783
[Patent Document 3] WO03/099813 pamphlet
[Patent Document 4] WO2004/011459 pamphlet
[Patent Document 5] WO2004/011611 pamphlet
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
An object of the present invention is to provide an effective process for total synthesis of pladienolide B and pladienolide D having excellent anti-tumor activity and to provide useful intermediates in the above-described process.
Measure for Solving the Problem
In view of the above circumstances, the present inventors have conducted intensive studies and as a result found an effective process for total synthesis of pladienolide B and pladienolide D and useful intermediates in the above-described process and thus completed the present invention.
That is, the present invention provides,
[1] A process for producing a compound represented by Formula (1):




wherein P1 means a hydrogen atom or a protecting group for hydroxy group; and R1 means a hydrogen atom or a hydroxy group, characterized by comprising reacting a compound represented by Formula (2):





wherein P1 and R1 are the same as defined above, with an acetylating agent in the presence of a base;

[2] The production process according to [1], wherein the acetylating agent is acetic anhydride;

[3] The production process according to [1] or [2], wherein the base is a combination of triethylamine with 4-dimethylaminopyridine;

[4] The production process according to any one of [1] to [3] wherein the compound represented by Formula (2) in which P1 and R1 are hydrogen atoms is obtained by removing protecting groups for hydroxy group at 3- and 21-positions of a compound represented by Formula (6):





wherein P2 means a protecting group for hydroxy group; P3 means a protecting group for hydroxy group; and R2 means a phenyl group which may have a substituent, to obtain a compound represented by Formula (5):





wherein R2 is the same as defined above, subsequently protecting hydroxy groups at the 3- and 21-positions of Compound (5) to obtain a compound represented by Formula (4):





wherein P4 and P5 mean protecting groups for hydroxy group; and R2 is the same as defined above, subsequently removing protecting groups for hydroxy group at 6- and 7-positions of Compound (4)>—R2 to obtain a compound represented by Formula (3):





wherein P4 and P5 are the same as defined above, and subsequently removing protecting groups at 3- and 21-positions of Compound (3);

[5] A process for producing a compound represented by Formula (6):





wherein P2, P3 and R2 are the same as defined below, characterized by comprising reacting a compound represented by Formula (7):





wherein P3 means a protecting group for hydroxy group; and Het means a 1-phenyl-1H-tetrazol-5-yl group, with a compound represented by Formula (8):





wherein P2 means a protecting group for hydroxy group; and R2 means a phenyl group which may have substituents, in the presence of a base;

[6] The production process according to [5], wherein the base is potassium bis(trimethylsilyl)amide;

[7] A process for producing a compound represented by Formula (9):





wherein P2, P6 and R2 are the same as defined below, characterized by comprising closing a ring in a compound represented by Formula (10):





wherein P2 means a protecting group for hydroxy group; R2 means a phenyl group which may have substituents; and P6 means a protecting group for hydroxy group, in the presence of a catalyst;

[8] The production process according to [7], wherein the catalyst is [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium;

[9] A process for producing a compound represented by Formula (11):





wherein P1, P7, P8, P9 and R1 are the same as defined below, characterized by comprising reacting a compound represented by Formula (12):





wherein P7 means a hydrogen atom or a protecting group for hydroxy group; and R1 means a hydrogen atom or a hydroxy group) and a compound represented by Formula (13):





wherein P1 means a hydrogen atom or a protecting group for hydroxy group; P8 means a hydrogen atom, an acetyl group or a protecting group for hydroxy group; P9 means a hydrogen atom or a protecting group for hydroxy group; or P8 and P9 may form together a group represented by a formula:





wherein R5 means a phenyl group which may have substituents, in the presence of a catalyst;

[10] The production process according to [9], wherein the catalyst is [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium or tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride;

[11] A compound represented by Formula (3-1):





wherein P41 and P51 may be the same or different and mean a hydrogen atom or a protecting group for hydroxy group, provided that both of P41 and P51 are or either one of P41 or P51 is a protecting group for hydroxy group, or a salt thereof;

[12] A compound represented by Formula (4,5,6-1):





wherein P241 means a hydrogen atom or a protecting group for hydroxy group; P351 means a hydrogen atom or a protecting group for hydroxy group; and R21 means a phenyl group which may have substituents, or a salt thereof;

[13] A compound represented by Formula (7-1):





wherein P31 means a hydrogen atom or a protecting group for hydroxy group; and Het means a 1-phenyl-1H-tetrazol-5-yl group, or a salt thereof;

[14] A compound represented by Formula (8-1):





wherein P21 means a hydrogen atom or a protecting group for hydroxy group; R21 means a phenyl group which may have substituents; and R41 means a formyl group or a group represented by —CH2OP61, wherein P61 means a hydrogen atom or a protecting group for hydroxy group, or a salt thereof;

[15] A compound represented by Formula (10-1):





wherein P21 means a hydrogen atom or a protecting group for hydroxy group; and P61 means a hydrogen atom or a protecting group for hydroxy group; and R21 means a phenyl group which may have substituents, or a salt thereof;

[16] A compound represented by Formula (12-1):





wherein P71 means a hydrogen atom or a protecting group for hydroxy group; and R11 means a hydrogen atom or a hydroxy group, or a salt thereof;

[17] A compound represented by Formula (13-1):





wherein P11 means a hydrogen atom or a protecting group for hydroxy group; Pn means a hydrogen atom, an acetyl group or a protecting group for hydroxy group; P91 means a hydrogen atom or a protecting group for hydroxy group; or Pn and P91 may form together a group represented by a formula:





wherein R51 means a phenyl group which may have substituents, or a salt thereof;

[18] A process for producing a compound represented by Formula (11′):





wherein P1, P8, P9, R6, R7 and R8 are the same as defined below, characterized by comprising reacting a compound represented by Formula (12′):





wherein R6 means a hydrogen atom or a linear C1-10 alkyl group which may have a substituent; R7 means a hydrogen atom or a methyl group; and R8 means a hydrogen atom or a hydroxy group, with a compound represented by Formula (13):





wherein P1 means a hydrogen atom or a protecting group for hydroxy group; P8 means a hydrogen atom, an acetyl group or a protecting group for hydroxy group; and P9 means a hydrogen atom or a protecting group for hydroxy group; or P8 and P9 may form together a group represented by a formula:





wherein R5 means a phenyl group which may have substituents, in the presence of a catalyst.

[19] A compound represented by Formula (14):





wherein P711 means a hydrogen atom or a protecting group for hydroxy group; and P111 means hydrogen atom or hydroxy group; and RA means a formyl group or a group represented by —CH2OH, or a salt thereof.

[20] A compound represented by Formula (15):





Wherein P712 means a hydrogen atom or a protecting group for hydroxy group; and R112 means a hydrogen atom or a hydroxy group, or a salt thereof.

[21] A compound represented by Formula (16):





wherein P211 means a hydrogen atom or a protecting group for hydroxy group; and P811 means a hydrogen atom, an acetyl group or a protecting group for hydroxy group; and P911 means a hydrogen atom or a protecting group for hydroxy group; and R411 means a formyl group or a group represented by —CH2OP611 (wherein P611 means a hydrogen atom or a protecting group for hydroxy group), or a salt thereof.

EFFECT OF THE INVENTION
Pladienolide B and pladienolide D and various kinds of pladienolide derivatives can be effectively synthesized by using a process for total synthesis of pladienolide B and pladienolide D and useful intermediates in the above-described process according to the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinbelow, meaning of terms, symbols and the like described in this specification are described and the present invention is described in detail.
The compounds of the present invention or salts thereof may be any of anhydrides, hydrates or solvates.
The “acetylating agent” to be used for producing Compound (1) from Compound (2) includes acetic anhydride and acetyl chloride, and preferably it is acetic anhydride.
The “base” to be used for producing Compound (1) from Compound (2) includes an organic base such as triethylamine, diisopropylethylamine and pyridine, etc. or a combination of the above organic base with 4-dimethylaminopyridine, and preferably it is a combination of triethylamine with 4-dimethylaminopyridine, a combination of diisopropylethylamine with 4-dimethylaminopyridine or a combination of pyridine with 4-dimethylaminopyridine, and more preferably it is a combination of triethylamine with 4-dimethylaminopyridine.
The “base” to be used for producing Compound (6) from Compound (7) and Compound (8) includes potassium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, lithium bis(trimethylsilyl)amide, etc. and preferably it is potassium bis(trimethylsilyl)amide.
The “catalyst” to be used for producing Compound (9) by closing a ring in Compound (10) includes [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(0-isopropoxyphenylmethylene)ruthenium (following formula (a)), tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride (following formula (b)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-5-nitrophenylmethylene)ruthenium (following formula (c)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-3-phenylphenylmethylene)ruthenium (following formula (d)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,2′-diisopropoxy-1,1′-binaphthalene-3-ylmethylene)ruthenium (following formula (e)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-methoxyphenylmethylene)ruthenium (following formula (f)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,4,5-trimethoxyphenylmethylene)ruthenium (following formula (g)), tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-2,3-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride (following formula (h)), bistricyclohexylphosphine[3,3-diphenylprop-2-en-1-ylidene]ruthenium (IV) dichloride (following formula (1)), and bis[3-bromopyridine][1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene][benzylidene]ruthenium (IV) dichloride (following formula (j)) and preferably it is [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium (following Formula (a)).










The “catalyst” to be used for producing Compound (11) from Compound (12) and Compound (13) and for producing Compound (11′) from Compound (12′) and Compound (13) includes [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene) ruthenium (following formula (a)), tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride (following formula (b)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-5-nitrophenylmethylene)ruthenium (following formula (c)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-3-phenylphenylmethylene)ruthenium (following formula (d)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,2′-diisopropoxy-1,1′-binaphthalene-3-ylmethylene)ruthenium (following formula (e)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-methoxyphenylmethylene)ruthenium (following formula (f)), [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,4,5-trimethoxyphenylmethylene)ruthenium (following formula (g)), tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-2,3-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride (following formula (h)), bistricyclohexylphosphine[3,3-diphenylprop-2-en-1-ylidene]ruthenium (IV) dichloride (following formula (i)), bis[3-bromopyridine][1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene][benzylidene]ruthenium (IV) dichloride (following formula (j)), bistricyclohexylphosphine[benzylidene]ruthenium (IV) dichloride (following formula (k)), and 2,6-diisopropylphenylimidoneophylidenemolybdenium bis(hexafluoro-t-butoxide) (following formula (l)) and preferably it is [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium (following formula (a)) and tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride (following formula (b)).










The “protecting group for hydroxy group” as used in this specification is not limited particularly as long as it is a group normally used as a protecting group for hydroxy group in organic synthesis and specific examples thereof include silyl type protecting groups such as tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triethylsilyl group, triisopropylsilyl group, trimethylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, di-tert-butylmethylsilyl group, diphenylmethylsilyl group, trimethylsilylethoxymethyl group and trimethylsilylethyl group, alkoxyalkyl type protecting groups such as methoxymethyl group, 2-methoxyethoxymethyl group, 2,2,2-trichloroethoxymethyl group, 1-ethoxyethyl group, 1-methyl-1-methoxyethyl group and tetrahydropyranyl group, benzyl type protecting groups such as benzyl group, 4-methoxybenzyl group, 3,4-dimethoxybenzyl group, 2,5-dimethoxybenzyl group, 2,3,4-trimethoxybenzyl group, 3,4,5-trimethoxybenzyl group, 2-nitrobenzyl group, 4-nitrobenzyl group, 4-chlorobenzyl group, 2,6-dichlorobenzyl group, 4-cyanobenzyl group, diphenylmethyl group and triphenylmethyl group, acetyl type protecting groups such as acetyl group, chloroacetyl group, dichloroacetyl group, trichloroacetyl group, fluoroacetyl group, difluoroacetyl group, trifluoroacetyl group, bromoacetyl group, tribromoacetyl group, methoxyacetyl group, pivaloyl group and benzoyl group, alkoxycarbonyl type protecting groups such as methoxycarbonyl group, 2,2,2-trichloroethoxycarbonyl group and benzyloxycarbonyl group.
Preferable examples of “protecting group for hydroxy group” in P1 and P11 include tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triethylsilyl group, triisopropylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, methoxymethyl group, 1-ethoxyethyl group, tetrahydropyranyl group, benzyl group, benzoyl group, etc. and more preferably it is tert-butyldimethylsilyl group and triethylsilyl group.
Preferable examples of “protecting group for hydroxy group” in P2, P21, and P211 include tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triethylsilyl group, triisopropylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, 1-ethoxyethyl group etc. and more preferably it is tert-butyldimethylsilyl group.
Preferable examples of “protecting group for hydroxy group” in P3 include tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triisopropylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, etc. and more preferably it is tert-butyldimethylsilyl group, diethylisopropylsilyl group and dimethylisopropylsilyl group, and still more preferably it is diethylisopropylsilyl group.
Preferable examples of “protecting group for hydroxy group” in P4 and P5 include chloroacetyl group, dichloroacetyl group, trichloroacetyl group, fluoroacetyl group, difluoroacetyl group, trifluoroacetyl group, bromoacetyl group, tribromoacetyl group, etc. and more preferably it is dichloroacetyl group.
Preferable examples of “protecting group for hydroxy group” in P241 include tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triethylsilyl group, triisopropylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, chloroacetyl group, dichloroacetyl group, trichloroacetyl group, fluoroacetyl group, difluoroacetyl group, trifluoroacetyl group, bromoacetyl group, tribromoacetyl group, etc. and more preferably it is tert-butyldimethylsilyl group and dichloroacetyl group.
Preferable examples of “protecting group for hydroxy group” in P351 include tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triisopropylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, chloroacetyl group, dichloroacetyl group, trichloroacetyl group, fluoroacetyl group, difluoroacetyl group, trifluoroacetyl group, bromoacetyl group and tribromoacetyl group, and more preferably it is tert-butyldimethylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, dichloroacetyl group, etc. and still more preferably it is diethylisopropylsilyl group and dichloroacetyl group.
Preferable examples of “protecting group for hydroxy group” in P6, P61 and P611 include 4-methoxybenzyl group, 3,4-dimethoxybenzyl group, 2,5-dimethoxybenzyl group, 2,3,4-trimethoxybenzyl group, 3,4,5-trimethoxybenzyl group, etc. and more preferably it is 4-methoxybenzyl group.
Preferable examples of “protecting group for hydroxy group” in P7, P71, P711 and P712 include tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triisopropylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, triethylsilyl group etc. and preferably it is tert-butyldimethylsilyl group, diethylisopropylsilyl group and dimethylisopropylsilyl group, triethylsilyl group and more preferably it is diethylisopropylsilyl group.
Preferable examples of “protecting group for hydroxy group” in P8, P81 and P811 include tert-butyldimethylsilyl group, tert-butyldiphenylsilyl group, triethylsilyl group, triisopropylsilyl group, diethylisopropylsilyl group, dimethylisopropylsilyl group, methoxymethyl group, 1-ethoxyethyl group, tetrahydropyranyl group, benzyl group, benzoyl group, etc.
Preferable examples of “protecting group for hydroxy group” in P9, P91 and P911 include methoxymethyl group, 1-ethoxyethyl group, etc.
Specific examples of “phenyl group which may have a halogen atom” in R2 and R5 include phenyl group, 4-chlorophenyl group, 4-bromophenyl group, etc. and preferably it is phenyl group.
Specific examples of “phenyl group which may have a substituent” in R21 and R51 include phenyl group, 4-chlorophenyl group, 4-bromophenyl group, 4-nitrophenyl group, 4-methoxyphenyl group, 2,4-dimethoxyphenyl group, 3,4-dimethoxyphenyl group, etc. and preferably it is phenyl group.
Specific examples of “linear C1-10 alkyl group” in R6 include methyl group, ethyl group, 1-propyl group, 1-butyl group, 1-pentyl group, 1-hexyl group, 1-heptyl group, 1-octyl group, 1-nonyl group, 1-decyl, etc. and preferably it is 1-heptyl group.
Specific examples of “substituent” in R6 include hydroxy group which may be protected, epoxy group, oxo group, methyl group, methoxy group, phenyl group, tetrahydrofuryl group which may have a methyl group or a hydroxy group which may be protected, etc. and preferably it is hydroxy group, epoxy group, methyl group.
“Het” is 1-phenyl-1H-tetrazol-5-yl group specifically in the above formula, but besides, it may be benzothiazol-2-yl group, etc. and preferably it is 1-phenyl-1H-tetrazol-5-yl group.
The “salt” as used in this specification is not particularly limited as long as it can form a salt of the compound of the present invention, and for example, it includes salts with inorganic bases and, among them, pharmacologically acceptable salts are desirable.
Preferable examples of salt with an inorganic base include alkali metal salt such as lithium salt, sodium salt, and potassium salt, alkaline earth metal salt such as calcium salt and magnesium salt, aluminum salt, and ammonium salt.
The process for production and examples of the present invention are described below in detail. The list of abbreviation used in process for production and examples is shown below.
A List of Abbreviation
Bn: benzyl
Et: ethyl
DEIPS: Diethylisopropylsilyl
DME: 1,2-dimethoxyethane
DMF: N,N-dimethylformamide
Me: methyl
Ph: phenyl
PMB: p-methoxybenzyl; 4-methoxybenzyl
TBS: tert-butyldimethylsilyl
TES: triethylsilyl
THF: tetrahydrofuran
Ts: p-toluenesulfonyl
Production Process 1: Process for Producing Compound (9) Using Cyclization Reaction by Olefin Metathesis




This step is a step to produce Compound (9) by closing a ring in Compound (10) in a solvent in the presence of a catalyst in the presence or absence of a chemical reagent.
This step can be performed by a commonly used method described in a literature (Handbook of Metathesis Vol. 1-3, Grubbs, R. H. Ed., WILEY-VCH, 2003), etc. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step 8] of the Example described below.
This reaction can be performed in a stream of or under atmosphere of an inert gas such as nitrogen and argon.
For Compound (10), Compound (P16) described in the Example described below or a compound which can be easily produced from a commercially available compound by the method which those skilled in the art usually perform can be used.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, for example, aromatic hydrocarbon solvents such as benzene, toluene, xylene, chlorobenzene and dichlorobenzene, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane chloroform and carbon tetrachloride can be used and preferably it is an aromatic hydrocarbon solvent such as benzene, toluene, xylene, chlorobenzene and dichlorobenzene.
The above catalyst means [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium, tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-5-nitrophenylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-3-phenylphenylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,2′-diisopropoxy-1,1′-binaphthalene-3-ylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-methoxyphenylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,4,5-trimethoxyphenylmethylene)ruthenium, tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-2,3-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride, bistricyclohexylphosphine[3,3-diphenylprop-2-en-1-ylidene]ruthenium (IV) dichloride, and bis[3-bromopyridine][1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene][benzylidene]ruthenium (IV) dichloride and the like but preferably it is [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium.
The above catalyst can be used in 0.001 to 1 time molar equivalent to Compound (10), and preferably it can be used in 0.01 to 1 molar equivalent.
The above chemical reagent means 2,6-di-tert-butyl-4-methylphenol (BHT), 1,4-benzoquinone, titanium triisopropoxide, etc.
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is 40° C. to reflux temperature (internal temperature of the reaction vessel), and more preferably it is 80° C. to reflux temperature (internal temperature of the reaction vessel) and still more preferably it is reflux temperature (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature for 0.5 to 48 hours after adding the chemical reagents, and it is more preferable to stir for 1 to 8 hours, and it is still more preferable to stir for about 5 hours.
Production Process 2: Process for Producing Compound (6) Using Julia Coupling




This step is a step to produce Compound (6) by reacting Compound (7) and Compound (8) in a solvent in the presence of a base.
This step can be performed by a commonly used method described in a literature (Blakemore, P. R.; Cole, W. J.; Kociensky, P. J.; Morley, A., Synlett, 1998, 26-28), etc. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step 17] of the Example described below.
This reaction can be performed in a stream of or under atmosphere of an inert gas such as nitrogen and argon.
For Compound (7), Compound (P35) described in the Example described below or a compound which can be easily produced from a commercially available compound by the method which those skilled in the art usually perform can be used.
For Compound (8), Compound (P19) described in the Example described below or a compound which can be easily produced from a commercially available compound by the method which those skilled in the art usually perform can be used.
Compound (8) can be used in 1 to 3 times molar equivalent to Compound (7), and preferably it can be used in 1 to 2 molar equivalents, more preferably it can be used in 1.5 molar equivalents.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, but, for example, ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane and diethyl ether, aromatic hydrocarbon solvents such as benzene, toluene and xylene, amide solvents such as N,N-dimethylformamide or mixed solvents of a solvent mentioned above with hexamethylphosphoramide (HMPA) or N,N′-dimethylpropyleneurea (DMPU) can be used and preferably it is an ether solvent such as tetrahydrofuran, 1,2-dimethoxyethane and diethyl ether.
The above-described base means potassium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, lithium bis(trimethylsilyl)amide, lithium diisopropylamide etc. and preferably it is potassium bis(trimethylsilyl)amide.
The above-described base can be used in 1 to 10 times molar equivalent to Compound (7), and preferably it can be used in 1 to 3 molar equivalents, more preferably it can be used in 2 molar equivalents.
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is −78° C. to −60° C. (internal temperature of the reaction vessel), and more preferably it is −78° C. (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature for 0.5 to 12 hours after adding the chemical reagents, and it is more preferable to stir for about 1 hour.
Production Process 3: Conversion from Compound (6) to Compound (2) (the Case where P1 and R1 are Hydrogen Atoms)
(a) Conversion from Compound (6) to Compound (5)




This step is a step to remove protecting groups of hydroxy group at 3- and 21-positions of Compound (6) in a solvent in the presence of a chemical reagent to produce Compound (5).
This step can be performed by a commonly used method described in a literature (Protective Groups in Organic Synthesis 3rd Edition, Green, T. W.; Wuts, P. G. M., Wiley-interscience, 1999), etc. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step 17] of the Example described below.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, but, for example, ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane and diethyl ether, alcohol solvents such as methanol and ethanol, acetonitrile, water, etc. can be used and preferably it is an ether solvent such as tetrahydrofuran, 1,2-dimethoxyethane and diethyl ether.
As for the chemical reagent mentioned above, for example, inorganic acids such as hydrochloric acid, sulfuric acid, hydrofluoric acid and perchloric acid, organic acids such as p-toluenesulfonic acid, pyridinium p-toluenesulfonate (PPTS), trifluoromethanesulfonic acid, methanesulfonic acid, acetic acid and trifluoroacetic acid, fluoride ion type chemical reagents such as tetra-n-butylammonium fluoride, potassium fluoride, cerium fluoride, hydrogen fluoride, hydrogen fluoride-pyridine can be used and preferably it is a fluoride ion type chemical reagent such as tetra-n-butylammonium fluoride, potassium fluoride, cerium fluoride, hydrogen fluoride and hydrogen fluoride-pyridine.
The above-described chemical reagent can be used in 2 to 10 molar equivalents to Compound (6), and preferably it can be used in 2 to 5 molar equivalents.
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is −20° C. to 50° C. (internal temperature of the reaction vessel), and more preferably it is 0° C. to 40° C. (internal temperature of the reaction vessel), and still more preferably it is room temperature (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature for 0.5 to 48 hours after adding the chemical reagents, and it is more preferable to stir for 0.5 to 12 hours, and it is still more preferable to stir for about 1 hour.
(b) Conversion from Compound (5) to Compound (4)




This step is a step to protect hydroxy groups at 3- and 21-positions of Compound (5) in a solvent in the presence of a chemical reagent and a base to produce Compound (4).
This step can be performed by a commonly used method described in a literature (Protective Groups in Organic Synthesis 3rd Edition, Green, T. W.; Wuts, P. G. M., Wiley-interscience, 1999), etc. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step 18] of the Example described below.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, but, for example, ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane, diethyl ether, tert-butyl methyl ether and cyclopentyl methyl ether, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane and chloroform, etc. can be used and preferably it is a halogenated hydrocarbon solvent such as dichloromethane, 1,2-dichloroethane and chloroform.
As for the chemical reagent mentioned above, for example, chloroacetic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, bromoacetic anhydride, chloroacetyl chloride, dichloroacetyl chloride, trichloroacetyl chloride, fluoroacetyl chloride, difluoroacetyl chloride, trifluoroacetyl chloride, bromoacetyl chloride can be used and preferably it is dichloroacetic anhydride.
The above-described chemical reagent can be used in 2 to 10 molar equivalents to Compound (5), and preferably it can be used in 2 to 5 molar equivalents.
The above-described base means an organic base such as triethylamine, diisopropylethylamine and pyridine or a combination of the above organic base with 4-dimethylaminopyridine, and preferably it is a combination of triethylamine, diisopropylethylamine or pyridine and 4-dimethylaminopyridine, and more preferably it is a combination of triethylamine with 4-dimethylaminopyridine.
The above-described base can be used in 2 to 10 molar equivalents to Compound (5) (when 4-dimethylaminopyridine is used, 4-dimethylaminopyridine in 0.01 to 1 molar equivalent to Compound (5)), and preferably it can be used in 2 to 3 molar equivalents (0.01 to 0.1 molar equivalent when 4-dimethylaminopyridine is used).
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is −20° C. to −50° C. (internal temperature of the reaction vessel), and more preferably it is 0° C. to 40° C. (internal temperature of the reaction vessel), and still more preferably it is room temperature (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature for 5 minutes to 24 hours after adding the chemical reagents, and it is more preferable to stir for 0.5 to 3 hours, and it is still more preferable to stir for 1 to 2 hours.
(c) Conversion from Compound (4) to Compound (3)




This step is a step to remove protecting groups of hydroxy group at 6- and 7-positions of Compound (4) in a solvent in the presence of a chemical reagent to produce Compound (3).
This step can be performed by a commonly used method described in a literature (Protective Groups in Organic Synthesis 3rd Edition, Green, T. W.; Wuts, P. G. M., Wiley-interscience, 1999), etc. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step 18] of the Example described below.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, but, for example, alcohol solvents such as methanol and ethanol, water, etc. can be used and preferably it is an alcohol solvent such as methanol and ethanol.
As for the chemical reagent mentioned above, for example, inorganic acids such as hydrochloric acid, sulfuric acid, hydrofluoric acid and perchloric acid, organic acids such as p-toluenesulfonic acid, pyridinium p-toluenesulfonate (PPTS), trifluoromethanesulfonic acid, methanesulfonic acid, acetic acid and trifluoroacetic acid, etc. can be used and preferably it is pyridinium p-toluenesulfonate (PPTS).
The above-described chemical reagent can be used in 0.05 to 20 times molar equivalent to Compound (4), and preferably it can be used in 0.1 to 10 molar equivalents, and more preferably it can be used in 1 to 2 molar equivalents.
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is 0° C. to 50° C. (internal temperature of the reaction vessel), and more preferably it is room temperature (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature for 0.5 to 96 hours after adding the chemical reagents, and it is more preferable to stir for about 48 hours.
(d) Conversion from Compound (3) to Compound (2) (the Case where P1 and R1 are Hydrogen Atoms)




This step is a step to remove protecting groups of hydroxy group at 3- and 21-positions of Compound (3) in a solvent in the presence of a chemical reagent to produce Compound (2) (the case where P1 and R1 are hydrogen atoms).
This step can be performed by a commonly used method described in a literature (Protective Groups in Organic Synthesis 3rd Edition, Green, T. W.; Wuts, P. G. M., Wiley-interscience, 1999), etc. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step 18] of the Example described below.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, but, for example, alcohol solvents such as methanol and ethanol, water, etc. can be used and preferably it is an alcohol solvent such as methanol and ethanol.
As for the chemical reagent mentioned above, for example, inorganic bases such as potassium carbonate, sodium carbonate and cesium carbonate, organic bases such as sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, sodium tert-butoxide and potassium tert-butoxide can be used and preferably it is an inorganic base such as potassium carbonate, sodium carbonate and cesium carbonate.
The above-described chemical reagent can be used in 0.01 to 10 molar equivalents to Compound (3), and preferably it can be used in 0.1 to 2 molar equivalents, and more preferably it can be used in 1 to 1.5 molar equivalents.
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is −20° C. to 70° C. (internal temperature of the reaction vessel), and more preferably it is 0° C. to 50° C. (internal temperature of the reaction vessel), and still more preferably it is room temperature (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature for 5 minutes to 24 hours after adding the chemical reagents, and it is more preferable to stir for 10 minutes to 12 hours.
Production Process 4: Process for Producing Compound (1) Using Acetylation Reaction




This step is a step to produce Compound (1) by acetylating a hydroxy group at 7-position of Compound (2) in a solvent in the presence of an acetylating agent and a base.
This step can be performed by a commonly used method. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step 19] of the Example described below.
This reaction can be performed in a stream of or under atmosphere of an inert gas such as nitrogen and argon.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, for example, ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane, diethyl ether, tert-butyl methyl ether and cyclopentyl methyl ether, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane and chloroform, etc. can be used and preferably it is a halogenated hydrocarbon solvent such as dichloromethane, 1,2-dichloroethane and chloroform.
The above acetylating agent means acetic anhydride and acetyl chloride and preferably it is acetic anhydride.
The above-described acetylating agent can be used in 1 to 5 molar equivalents to Compound (2), and preferably it can be used in 0.5 to 1.5 molar equivalents, and more preferably it can be used in 0.8 to 1.2 molar equivalents.
The above-described base means an organic base such as triethylamine, diisopropylethylamine and pyridine or a combination of the above organic base with 4-dimethylaminopyridine, and preferably it is a combination of triethylamine, diisopropylethylamine or pyridine and 4-dimethylaminopyridine, and more preferably it is a combination of triethylamine with 4-dimethylaminopyridine.
The above-described base can be used in 0.5 to 10 molar equivalents to Compound (2) (when 4-dimethylaminopyridine is used, 4-dimethylaminopyridine in 0.01 to 1 molar equivalent to Compound (2)), and preferably it can be used in 0.5 to 5 molar equivalents (0.1 to 1 molar equivalent when 4-dimethylaminopyridine is used), and more preferably it can be used in 0.8 to 1.2 molar equivalents (0.1 to 0.5 molar equivalent when 4-dimethylaminopyridine is used).
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is −20° C. to room temperature (internal temperature of the reaction vessel), and more preferably it is about 0° C. (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature 0.5 to 24 hours after adding the chemical reagents, and it is more preferable to stir for 0.5 to 8 hours, and it is still more preferable to stir for about 1 hour.
Production Process 5: Process for Producing Compound (11) and Compound (11′) Using Cross Coupling Reaction by Olefin Metathesis




This step is a step to produce Compound (11) or Compound (11′) by reacting Compound (12) or Compound (12′) with Compound (13) in a solvent in the presence of a catalyst.
This step can be performed by a commonly used method described in a literature (Handbook of Metathesis Vol. 1-3, Grubbs, R. H. Ed., WILEY-VCH, 2003), etc. More specifically, this step can be performed with reference to the reaction conditions, work up procedures and purification method described in [Step D6] of the Example described below.
This reaction can be performed in a stream of or under atmosphere of an inert gas such as nitrogen and argon.
For Compound (12), Compound (Q9) described in the Example described below or a compound which can be easily produced from a commercially available compound by the method which those skilled in the art usually perform can be used.
For Compound (12′), Compound (Q14) described in the Example described below or a compound which can be easily produced from a commercially available compound by the method which those skilled in the art usually perform can be used.
For Compound (13), Compound (Q12) described in the Example described below or a compound which can be easily produced from a commercially available compound by the method which those skilled in the art usually perform can be used.
Compound (12) or Compound (12′) can be used in 1 to 10 molar equivalents to Compound (13), and preferably it can be used in 1.5 to 4 molar equivalents, and more preferably it can be used in 2 to 3 molar equivalents.
As for the solvent mentioned above, there is no particular limitation as long as it can dissolve starting materials to some extent and does not obstruct the reaction, but, for example, aromatic hydrocarbon solvents such as benzene, toluene, xylene, chlorobenzene and dichlorobenzene, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane, chloroform and carbon tetrachloride, water, methanol, etc. can be used and preferably it is a halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane, chloroform and carbon tetrachloride.
The above catalyst means [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene) ruthenium, tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-5-nitrophenylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-isopropoxy-3-phenylphenylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,2′-diisopropoxy-1,1′-binaphthalene-3-ylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2-methoxyphenylmethylene)ruthenium, [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(2,4,5-trimethoxyphenylmethylene)ruthenium, tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-2,3-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride, bistricyclohexylphosphine[3,3-diphenylprop-2-en-1-ylidene]ruthenium (IV) dichloride, bis[3-bromopyridine][1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene][benzylidene]ruthenium (IV) dichloride, bistricyclohexylphosphine[benzylidene]ruthenium (IV) dichloride, and 2,6-diisopropylphenylimidoneophylidenemolybdenium bis(hexafluoro-t-butoxide) and the like but preferably it is [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium and tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride.
The above catalyst can be used in 0.001 to 1 molar equivalent to Compound (13), and preferably it can be used in 0.01 to 0.3 molar equivalent.
The reaction temperature usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction, and preferably it is 20° C. to refluxing temperature (internal temperature of the reaction vessel), and more preferably it is refluxing temperature (internal temperature of the reaction vessel).
The reaction time usually varies depending on starting materials, solvents and the other chemical reagents used in the reaction and reaction temperature, and it is preferable to stir the reaction solution at the above reaction temperature for 0.1 to 96 hours after adding the chemical reagents, and it is more preferable to stir for 0.5 to 12 hours, and it is still more preferable to stir for about 1 hour.
After the reaction of each of the above steps is completed, object compounds in each of the above steps can be taken from the reaction mixture by an usual manner.


EXAMPLES
Hereinbelow, Examples are described in order to facilitate the present invention to be understood, but, needless to say, the present invention is not limited to these.
Determination of Absolute Configuration of Pladienolide B
Test Example 1
Determination of Relative Configuration of Pladienolide B by NMR
[Method]
NMR information (1H-1H coupling constant, 1H-—C long range coupling constant and NOE correlation) which was necessary for determining relative configuration was obtained under the following conditions.
Device used: Unity INOVA 500 MHz (product of Varian) and
JNMα 600 MHz (product of JEOL)
Solvent: deuterated pyridine
Measurement temperature: 30° C.
Sample density: about 20 mg/mL
Measuring method: 1H-NMR, 13C-NMR, COSY, NOESY, HMQC,
HMBC, HETLOC, J-resolved-HMBC, 1H-decoupling
[Results]
NMR information shown in the following Table 1 to Table 3 was obtained. The relative configuration of five asymmetric carbons present in macrolactone ring moiety was determined to be (3R*,6R*,7S*,10S*,11S*) from 1H-1H coupling constant and NOE correlation. As for relative configuration of five asymmetric carbons present in side-chain moieties, analysis by J-based configuration analysis (N. Matsumori et al, J. Org. Chem., 64, 866-876, 1999) was performed based on 1H-1H coupling constant, 1H-13C long range coupling constant and NOE correlation, and was determined to be (16S*,18R*,19R*,20R*,21S*).
















TABLE 1








JHH multiplicity,
long range JCH,



position
δC
δH
J = Hz
J = Hz
NOESY*




















1
170.9
—
—
—
—


2α
40.2
2.7 
dd, 14.0, 3.2
—
H2β(s), H3(m), H4α(n),







H4β(n), H5α(n), H5β(w),


2β

2.78
dd, 14.0, 4.0
—
H2α(s), H3(w), H4α(n),







H4β(n), H5α(n), H5β(n),


3
69.8
4.1 
dddd, 10.0, 4.0,
2JH2β/C3 = 4,
H2α(m), H2β(w), H4α(w),





3.5, 3.5, 3.2
2JH2α/C3 < 2
H4β(n), H5α(w), H5β(n)


4α
30.8
1.95
dddd, 13.5, 13.2,
—
H2α(n), H2β(n), H3(w),





3.5, 3.5

H4β(s), H5α(m), H5β(o),







H7(n), H8(n), H9(n), 6-


4β

1.82
dddd, 13.5, 13.0,
—
H2α(n), H2β(n), H3(n),





10.0, 3.7

H4α(s), H5α(o), H5β(w),







H7(s), H8(n), H9(w), 6-CH3(n)


5α
37.7
1.71
ddd, 13.2, 13.0,
—
H2α(n), H2β(n), H3(w),





3.5

H4α(m), H4β(o), H5β(s),







H7(n), H8(n), H9(n), 6-CH3(s)


5β

2.11
ddd, 13.2, 13.2,
—
H2α(w), H2β(n), H3(n),





3.7

H4α(o), H4β(w), H5β(s),







H7(n), H8(w), H9(n), 6-CH3(n)


6
73
—

3JH8/C6 < 2
—


7
79.7
5.54
d, 9.8
3JH9/C7 = 6.5
H4α(n), H4β(s), H5α(n),







H5β(n), H8(w), H9(w),







H10(n), 6-CH3(m), 7-


8
127.4
6.27
dd, 15.2, 9.8
2JH7/C8 = 3
H4α(n), H4β(n), H5α(n),







H5β(w), H7(w), H9(w),







H10(n), H11(w), 6-CH3(n), 7-







COCH3(n), 10-CH3(m)


9
140.1
5.81
dd, 15.2, 10.0
3JH11/C9 = 2.5
H4α(n), H4β(w), H5α(n),







H5β(n), H7(w), H8(w),







H10(n), H11(w), 6-CH3(n), 7-







COCH3(n), 10-CH3(m)


10
40.9
2.67
ddq, 10.7, 10.0,
3JH8/C10 = 6,
H7(n), H8(w), H9(n), H11(w),





6.8
2JH9/C10 = 3,
6-CH3(n), 7-COCH3(n), 10-






2JH11/C10 = 3
CH3(s), 12-CH3(s)


11
82.9
5.33
d, 10.7
3JH9/C11 = 2.5,
H2α(n), H2β(n), H7(n), H8(n),






3JH13/C11 = 7
H9(w), H10(w), H13(w), 10-







CH3(s), 12-CH3(w)


12
132
—
—
2JH11/C12 = 2.5,
—






3JH14/C12 = 3





















TABLE 2








JHH multiplicity,
long range JCH,



position
δC
δH
J = Hz
J = Hz
NOESY*




















13
131.2
6.34
brd, 11.0
3JH11/C13 = 5
H10(n), H11(w), H14(o),







H15(w), 10-CH3, 12-CH3(w)


14
124.9
6.46
dd, 15.1, 11.0
—
H11(n), H13(o), H15(w),







H16(m), 12-CH3(s), 16-


15
141.7
5.73
dd, 15.1, 8.0
3JH13/C15 = 5,
H13(w), H14(w), H16(w),






3JH17β/C15 = 6
H17α(n), H17β(n), H18(w),






3JH17α/C15 = 3.5
12-CH3(n), 16-CH3(m)


16
35.8
2.54
dddq, 8.5, 8.0,
3JH14/C16 = 5.5,
H14(m), H15(w), H17α(n),





5.0, 6.8
2JH17β/C16 = 4
H17β(m), H18(m), H19(n), 16-






2JH17α/C16 = 4.5
CH3(s)


17α
40.1
1.56
ddd, 13.9, 8.5,
—
H14(n), H15(n), H16(n),





5.9

H17β(s), H18(w), H19(m), 16-


17β

1.7
ddd, 13.9, 5.9,
—
H14(n), H15(n), H16(m),





5.0

H17α(s), H18(m), H19(m), 16-







CH3(o)


18
56.9
2.88
ddd, 5.9, 5.9, 2.1
2JH17β/C18 = 7,
H15(w), H16(m), H17α(w),






2JH17α/C18 = 4
H17β(m), H19(w), H20(s), 16-






3JH20/C18 = 3.5
CH3(w), 20-CH3(m)


19
61.9
3.02
dd, 8.1, 2.1
3JH17β/C19 = 6,
H15(n), H16(n), H17α(m),






3JH17α/C19 = 2.5
H17β(m), H18(w), H20(m),






2JH20/C19 = 7.5,
H21(m), 16-CH3(n), 20-CH3(s)






3JH21/C19 = 3.5



20
42.1
1.45
ddq, 8.1, 4.0, 6.8
2JH21/C20 < 2
H17α(n), H17β(o), H18(s),







H19(m), H21(s), H22a(o),







H22b(o), H23 (s), 20-CH3(s)


21
73.6
3.98
ddd, 8.3, 4.4, 4.0
3JH19/C21 < 2,
H18(n), H19(m), H20(s),






2JH20/C21 < 2
H22a(m), H22b(s), H23(s),







H30(w)


22a
28.6
1.75
m
2JH21/C22 < 2
H19(n), H20(o), H21(m),







H22b(o), H23(s), 20-CH3(m)


22b

1.68
m

H19(n), H20(o), H21(s),







H22a(o), H23(s), H30(m)


23
11
1.08
t, 7.3
—
H20(s), H21(s), H22a(s),







H22(s), 20-CH3(o)





















TABLE 3








JHH multiplicity,
long range JCH,



position
δC
δH
J = Hz
J = Hz
NOESY*




















6-CH3
24.8
1.46
s
—
H4α(m), H4β(n), H5α(s),







H5β(n), H7(m), H8(n), 7-







COCH3(o)


7-COCH3
170.2
—
—
—
—


7-COCH3
21.1
1.96
s
—
H7(w), H8(n), H9(n), 6-CH3(o)


10-CH3
16.6
0.87
d, 6.8
3JH9/C10-Me < 2,
H8(n), H9(m), H10(s), H11(s),






3JH11/C10-Me < 2
H13(w), 12-CH3(w)


12-CH3
12
1.8
brs
3JH11/C12-Me = 4.5,
H10(s), H11(w), H13(w),






3JH13/C12-Me = 7.5
H14(s), H15(n), H27(w)


16-CH3
21.2
1.09
d, 6.8
—
H14(m), H15(m), H16(s),







H17α(w), H17β(o), H18(w)


20-CH3
10.8
1.15
d, 6.8
—
H18(m), H19(s), H20(s),







H21(w), H22a(m), H22b(m),





recorded in pyridine-d5, 30° C., C5D4HN(H3) = 7.22 ppm, C5D5N(C3) = 123.9 ppm


*s: strong; m: moderate; w: weak; n: not detected; o: obscured by overlapping signals






Test Example 2
MTPA Esterification of Pladienolide B
To a pyridine (3.0 ml) solution of pladienolide B (8 mg, 14.9 μmol), 4-dimethylaminopyridine (1 mg, 8.1 μmol) and (S)-MTPA chloride (25 mg, 99.2 μmol) were added and after allowed to stand still at room temperature for 12 hours, pyridine was evaporated and then water (10 ml) was added and the mixture was extracted with ethyl acetate (10 ml). The obtained organic layer was concentrated and then purified by preparative HPLC (J 'sphere ODS M-80, 20 mm I.D.×250 mm, acetonitrile: 0.15% trifluoroacetic acid aqueous solution=80:20→100:0, 9.0 ml/min) and rough MTPA ester fraction was concentrated to 1.5 ml. The concentrated fraction was purified by preparative HPLC (J 'sphere ODS M-80, 20 mm I.D.×250 mm, acetonitrile: water=60:40→100:0, 10.0 ml/min) and 3,21-di-(R)-MTPA ester (12.0 mg, 14.0 μmol, 94.0%) of pladienolide B was obtained.
In the same way, to a pyridine (3.0 ml) solution of pladienolide B (8 mg, 14.9 μmol), 4-dimethylaminopyridine (1 mg, 8.1 μmol) and (R)-MTPA chloride (25 mg, 99.2 μmol) were added and after allowed to stand still at room temperature for 12 hours, pyridine was evaporated and then water (10 ml) was added and the mixture was extracted with ethyl acetate (10 ml). The obtained organic layer was concentrated and then purified by preparative HPLC (J 'sphere ODS M-80, 20 mm I.D.×250 mm, acetonitrile: 0.15% trifluoroacetic acid aqueous solution=80:20→100:0, 9.0 ml/min) and rough MTPA ester fraction was concentrated to 1.5 ml. The concentrated fraction was purified by preparative HPLC (J 'sphere ODS M-80, 20 mm I.D.×250 mm, acetonitrile: water=60:40→100:0, 10.0 ml/min) and 3,21-di-(S)-MTPA ester (10.0 mg, 11.6 μmol, 82.9%) of pladienolide B was obtained.
Test Example 3
Determination of Absolute Configuration of Pladienolide B by Modified Mosher's Method
[Method]
NMR measurement of 3,21-di-(R)-MTPA ester and 3,21-di-(S)-MTPA ester of pladienolide B was performed under the following conditions.
Device used: JNMα 600 MHz (product of JEOL)
Solvent: deuterated chloroform
Measurement temperature: 30° C.
Sample density: about 5 mg/mL
Measuring method: 1H-NMR, COSY
[Results]
Assignment information of 1H-NMR signals shown in the following Table 4 for 3,21-di-(R)-MTPA ester and 3,21-di-(S)-MTPA ester of pladienolide B was obtained. As a result of having analyzed Δδ value (δS−δR) of each proton signal obtained from these chemical shifts, the absolute configuration of 3-position asymmetric carbon was determined to be R configuration, and the absolute configuration of 21-position asymmetric carbon was determined to be S configuration. From the above results and the results of the relative configuration determined by Test Example 1, the absolute configuration of ten asymmetric carbons present in pladienolide B was determined to be (3R,6R,7S,10S, 11S,16S,18R,19R,20R,21S).















TABLE 4







S-MTPA ester
R-MTPA ester
Δ δ



position
(δH)
(δH)
(S − R)




















2α
2.64
2.68
−0.04



2β
2.68
2.8
−0.12



3
5.12
5.08
0.04



4α
1.71
1.64
0.07



4β
1.54
1.5
0.04



5α
1.7
1.46
0.24



5β
1.7
1.7
±0.00



7
5.08
5.04
0.04



8
5.65
5.63
0.02



9
5.69
5.68
0.01



10
2.52
2.52
±0.00



11
5.05
5.06
−0.01



13
6.04
6.05
−0.01



14
6.22
6.22
±0.00



15
5.58
5.56
0.02



16
2.43
2.41
0.02



17α
1.46
1.4
0.06



17β
1.53
1.5
0.03



18
2.66
2.63
0.03



19
2.41
2.27
0.14



20
1.54
1.48
0.06



21
5.12
5.17
−0.05



22α
1.75
1.8
−0.05



22β
1.66
1.7
−0.04



23
0.83
0.91
−0.08



6-CH3
1.22
1.17
0.05



7-COCH3
2.1
2.08
0.02



10-CH3
0.87
0.86
0.01



12-CH3
1.71
1.72
−0.01



16-CH3
1.06
1.06
±0.00



20-CH3
0.89
0.83
0.06





recorded in chloroform-d, 30° C., CHCl3 = 7.27 ppm






Determination of Absolute Configuration of Pladienolide D
Test Example 4
Determination of Relative Configuration of Pladienolide D by NMR
[Method]
NMR information (1H-1H coupling constant and NOE correlation) which was necessary for determining relative configuration was obtained under the following conditions.
Device used: AVANCE 600 MHz (product of Bruker)
Solvent: deuterated pyridine
Measurement temperature: 30° C.
Sample density: about 20 mg/mL
Measuring method: 1H-NMR, 13C-NMR, COSY, NOESY, HMQC,
HMBC
[Results]
NMR information shown in the following Table 5 to Table 6 was obtained. The obtained 1H-1H coupling constant and NOE correlation pattern were similar to those of pladienolide B and therefore relative configuration of pladienolide D was determined to be (3R*,6R*,7S*,10S*,11S*,16R*,18R*,19R*, 20R*, 21S*).















TABLE 5








JHH multi-






plicity,



position
□C
□H
J = Hz
NOESY*



















1
171.3
—
—
—


2□
40.6
2.7
dd, 14.0, 3.2
H2□(s), H3(m), H4□(n),






H4□(n), H5□(n), H5□(w),


2□

2.77
dd, 14.0, 4.2
H2□(s), H3(n), H4□(n),






H4□(n), H5□(n), H5□(n),


3
70.2
4.09
m
H2□(m), H2□(n), H4□(w),






H4□(n), H5□(w), H5□(n)


4□
31.2
1.94
m
H2□(n), H2□(n), H3(w),






H4□(s), H5□(w), H5□(o),






H7(n), H8(n), H9(n), 6-CH3(m)


4□

1.8
m
H2□(n), H2□(n), H3(o),






H4□(s), H5□(o), H5□(w),






H7(s), H8(n), H9(w), 6-CH3(n)


5□
38.1
1.71
m
H2□(n), H2□(n), H3(w),






H4□(w), H4□(o), H5□(s),






H7(n), H8(n), H9(n), 6-CH3(m)


5□

2.1
ddd, 13.5,
H2□(w), H2□(n), H3(n),





13.5, 3.3
H4□(o), H4□(w), H5□(s),






H7(n), H8(w), H9(n), 6-CH3(n)


6
73.4
—

—


7
80.2
5.53
d, 9.8
H4□(n), H4□(s), H5□(n),






H5□(n), H8(w), H9(n), H10(n),






H11(n), 6-CH3(m), 7-


8
127.8
6.27
dd, 15.2, 9.8
H4□(n), H4□(n), H5□(n),






H5□(w), H7(w), H9(w),






H10(n), H11(n), 6-CH3(n), 7-






COCH3(n), 10-CH3(n)


9
140.5
5.82
dd, 15.2, 10.0
H4□(n), H4□(w), H5□(n),






H5□(n), H7(n), H8(w), H10(n),






H11(n), 6-CH3(n), 7-






COCH3(n), 10-CH3(m)


10
41.3
2.67
ddq, 10.7,
H7(n), H8(w), H9(n), H11(w),





10.0, 6.7
6-CH3(n), 7-COCH3(n), 10-






CH3(s), 12-CH3(s)


11
83.3
5.35
d, 10.7
H2□(n), H2□(n), H7(n), H8(n),






H9(n), H10(w), H13(w), 10-






CH3(s), 12-CH3(w)


12
133.3
—
—
—




















TABLE 6








JHH multi-






plicity,



position
□C
□H
J = Hz
NOESY*



















13
131.4
6.45
brd, 11.1
H10(n), H11(w), H14(m),






H15(n), 10-CH3(w), 12-CH3(w)


14
123.1
6.99
dd, 15.2, 11.1
H11(n), H13(m), H15(m), 12-






CH3(s), 16-CH3(m),


15
144.5
6.16
d, 15.2
H13(n), H14(m), H17□(n),






H17□(n), H18(w), 12-CH3(n),






16-CH3(m)


16
72.3
—




17□
46.5
1.96
dd, 13.8, 6.5
H15(n), H17□(s), H18(w),






H19(m), 16-CH3(m)


17□

2.25
dd, 13.8, 5.2
H15(n), H17□(s), H18(m),






H19(m), 16-CH3(m)


18
55.3
3.38
ddd, 6.5,
H15(w), H17□(w), H17□(m),





5.2, 2.0
H19(w), H20(s), 16-CH3(m),






20-CH3(m)


19
62.2
3.12
dd, 7.6, 2.0
H15(n), H17□(m), H17□(m),






H18(w), H20(w), H21(m), 16-






CH3(n), 20-CH3(s)


20
42.3
1.58
m
H17□(n), H17□(o), H18(s),






H19(w), H21(s), H22ab(o),






H23 (s), 20-CH3(s)


21
74.1
3.99
m
H18(n), H19(m), H20(s),






H22ab(m), H23(s), 20-CH3(w)


22ab
28.9
1.80-1.66
m
H19(n), H20(o), H21(m),






H23(s), 20-CH3(m)


23
11.4
1.07
t, 7.4
H20(s), H21(s), H22ab(s), 20-






CH3(o)


6-CH3
25.2
1.46
s
H4□(m), H4□(n), H5□(m),






H5□(n), H7(m), H8(n), 7-






COCH3(o)


7-COCH3
170.6
—
—
—


7-COCH3
21.5
1.96
s
H7(w), H8(n), H9(n), 6-CH3(o)


10-CH3
17.1
0.87
d, 6.7
H8(n), H9(m), H10(s), H11(s),






H13(w), 12-CH3(w)


12-CH3
12.4
1.78
brs
H10(s), H11(w), H13(w),






H14(s), H15(n), 10-CH3(w)


16-CH3
29.7
1.63
s
H14(m), H15(m), H16(s),






H17□(m), H17□(m), H18(m)


20-CH3
10.6
1.17
d, 7.0
H18(m), H19(s), H20(s),






H21(w), H22ab(m), H23(o)





recorded in pyridine-d5, 30° C., C5D4HN(H3) = 7.22 ppm, C5D5N(C3) = 123.9 ppm


*s: strong; m: moderate; w: weak; n: not detected; o: obscured by overlapping signals






Test Example 5
MTPA Esterification of Pladienolide D
A pyridine (262 μl) solution of pladienolide D (5.24 mg, 9.48 μmol) and a dichloromethane solution (2.0 ml) of 4-dimethylaminopyridine (82.2 mg, 0.67 mmol) were prepared. A part (100 μl, 3.62 μmol) of the pyridine solution of pladienolide D was taken and the dichloromethane solution (100 μl, 33.5 μmol) of 4-dimethylaminopyridine and (S)-MTPA chloride (10 mg, 39.7 μmol) were added and after stirred at room temperature for 30 minutes, 4-dimethylaminopyridine solution (100 μl, 33.5 μmol) and (S)-MTPA chloride (10 mg, 39.7 μmol) were further added and stirred at room temperature for 30 minutes. Dichloromethane (2.0 ml) and water (2.0 ml) were added to the reaction mixture and after stirred, the dichloromethane layer was separated and concentrated. The residue was purified by NH-silica gel column chromatography (ethyl acetate/hexane=3:1 mixed solvent), the obtained fraction of MTPA was concentrated by nitrogen gas spraying and then further dried under reduced pressure and 3,21-di-(R)-MTPA ester of pladienolide D was obtained.
In the same way, a part (100 μl, 3.62 μmol) of the pyridine solution of pladienolide D was taken and the dichloromethane solution (100 μl, 33.5 μmol) of 4-dimethylaminopyridine and (R)-MTPA chloride (10 mg, 39.7 μmol) were added and after stirred at room temperature for 30 minutes, 4-dimethylaminopyridine solution (100 μl, 33.5 μmol) and (R)-MTPA chloride (10 mg, 39.7 μmol) were further added and stirred at room temperature for 30 minutes. Dichloromethane (2.0 ml) and water (2.0 ml) were added to the reaction mixture and after stirred, the dichloromethane layer was separated and concentrated. The residue was purified by NH-silica gel column chromatography (ethyl acetate/hexane=3:1 mixed solvent), the obtained fraction of MTPA was concentrated by nitrogen gas spraying and then further dried under reduced pressure and 3,21-di-(S)-MTPA ester of pladienolide D was obtained.
Test Example 6
Determination of Absolute Configuration of Pladienolide D by Modified Mosher's Method
[Method]
NMR measurement of 3,21-di-(R)-MTPA ester and 3,21-di-(S)-MTPA ester of pladienolide D was performed under the following conditions.
Device used: INOVA 500 MHz (product of Varian)
Solvent: deuterated acetonitrile
Measurement temperature: 30° C.
Measuring method: 1H-NMR, COSY, TOCSY, ROESY
[Results]
Assignment information of 1H-NMR signals shown in the following Table 7 for 3,21-di-(R)-MTPA ester and 3,21-di-(S)-MTPA ester of pladienolide D was obtained. As a result of having analyzed Δδ value (δS−δR) of each proton signal obtained from these chemical shifts, the absolute configuration of 3-position asymmetric carbon was determined to be R configuration, and the absolute configuration of 21-position asymmetric carbon was determined to be S configuration. From the above results and the results of the relative configuration determined by Test Example 4, the absolute configuration of ten asymmetric carbons present in pladienolide D was determined to be (3R,6R,7S,10S, 11S,16R,18R,19R,20R,21S).















TABLE 7







S-MTPA ester
R-MTPA ester
Δ δ



position
(δH)
(δH)
(S − R)




















2α
2.61
2.7
−0.09



2β
2.67
2.71
−0.04



3
5.12
5.14
−0.02



4α
1.54
1.49
0.05



4β
1.66
1.49
0.17



5α
1.42
1.38
0.04



5β
1.61
1.59
0.02



7
4.99
4.93
0.06



8
5.67
5.67
±0.00



9
5.52
5.51
0.01



10
2.57
2.57
±0.00



11
4.91
4.94
−0.03



13
6.03
6.02
0.01



14
6.45
6.42
0.03



15
5.81
5.73
0.08



17α
1.57
1.45
0.12



17β
1.78
1.75
0.03



18
2.83
2.77
0.06



19
2.41
2.14
0.27



20
1.52
1.4
0.12



21
5.08
5.11
−0.03



22
1.65
1.69
−0.04



23
0.77
0.88
−0.11



6-CH3
1.14
1.1
0.04



7-COCH3
2.02
2.01
0.01



10-CH3
0.8
0.8
±0.00



12-CH3
1.72
1.72
±0.00



16-CH3
1.27
1.24
0.03



20-CH3
0.87
0.76
0.11





recorded in acetonitrile-d3, 30° C., CHD2CN = 1.93 ppm






Total Synthesis of Pladienolide B
Step 1
Synthesis of (4Z)-6-[(4-methoxybenzyl)oxy]-4-methylhex-4-enal]




(1) Synthesis of 1-({[(2Z)-3,7-dimethylocta-2,6-dien-1-yl]oxy}methyl)-4-methoxybenzene (P1)
Nerol (150 g, 972 mmol) was added dropwise to a DMF (1.501) suspension of sodium hydride (60%, 38.9 g, 973 mmol) under nitrogen gas stream at room temperature. The reaction solution was stirred at room temperature for one hour and then cooled to 0° C. After tetra-n-butyl ammonium iodide (35.9 g, 97.2 mmol) was added to the reaction solution, 4-methoxybenzyl chloride (148 g, 926 mmol) was added dropwise. The reaction solution was stirred at 0° C. for one hour and then at room temperature for six hours. Water was added to the reaction solution, which was then extracted with n-heptane. After the obtained organic layer was washed with water and brine (saturated solution of sodium chloride) sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=1:0→30:1→25:1) to obtain the title compound (246.7 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.58 (s, 3H), 1.67 (s, 3H), 1.75 (d, J=1.2 Hz, 3H), 2.00-2.12 (m, 4H), 3.80 (s, 3H), 3.97 (dd, J=1.0, 7.0 Hz, 1H), 4.43 (s, 2H), 5.04-5.12 (m, 1H), 5.40 (dt, J=1.2, 6.8 Hz, 2H), 6.85-6.89 (m, 2H), 7.25-7.28 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 17, 49, 23.36, 25.56, 26.59, 32.13, 55.06, 65.96, 71.62, 113.59, 121.82, 123.79, 129.24, 130.55, 131.69, 140.31, 159.00; IR (neat) 2964, 2913, 2855, 1612, 1512, 1247, 1093, 1067, 1037, 819 cm−1; HRMS C18H27O2 (M+H+) Calcd: 275.2011, Found: 275.2003.




(2) Synthesis of (4Z)-6-[(4-methoxybenzyl)oxy]-4-methylhex-4-enal (P2)
1-({[(2Z)-3,7-dimethylocta-2,6-dien-1-yl]oxy}methyl)-4-methoxybenzene (75.0 g, 273 mmol) was dissolved in dichloromethane (1.13 l) and pyridine (11.3 ml). This reaction solution was cooled to −78° C., to which ozone was bubbled (flow rate 2 l/min, electric voltage 90 V) for 170 minutes with stirring. After addition of dimethylsulfide (80.3 ml, 1.09 mol), the reaction solution was allowed to warm to room temperature and was stirred overnight. The reaction solution was concentrated under reduced pressure and the obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=4:1) and the title compound (36.9 g) was obtained as a colorless oil while 1-({[(2Z)-3,7-dimethylocta-2,6-dien-1-yl]oxy}methyl)-4-methoxybenzene (14.1 g) was recovered.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.75 (s, 3H), 2.36 (t, J=7.6 Hz, 2H), 2.47-2.55 (m, 2H), 3.81 (s, 3H), 3.98 (d, J=6.7 Hz, 2H), 4.43 (s, 2H), 5.46 (brt, J=6.7 Hz, 1H), 6.86-6.90 (m, 2H), 7.25-7.27 (m, 2H), 9.75 (t, J=1.2 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 22.99, 24.34, 42.11, 55.09, 65.61, 71.82, 113.62, 122.97, 129.29, 130.25, 138.43, 159.04, 201.63; IR (neat) 2935, 2835, 2727, 1722, 1612, 1514, 1249, 1072, 1035, 819 cm−1; HRMS C15H20NaO3 (M+Na+) Calcd: 271.1310, Found: 271.1322
Step 2
Synthesis of methyl (3R,6Z)-3-{[tert-butyl(dimethyl)silyl]oxy-8-[(4-methoxybenzyl)oxy]-6-methyloct-6-enoate




(1) Synthesis of (4R)-3-{(3R,6Z)-3-hydroxy-8-[(4-methoxybenzyl)oxy-6-methyloct-6-enoyl]-4-isopropyl-1,3-oxazolidin-2-one (P3)
This step was performed with reference to the literature (Fukuzawa, S.; Matsuzawa, H.; Yoshimitsu, S.; J. Org. Chem., 2000, 65(6), 1702-1706.). (R)—N-bromoacetyl-4-isopropyl-2-oxazolidinone used in this step was also prepared by the method described in this literature.
Anhydrous THF distilled by using lithium aluminum hydride immediately before use was used in this step.
After diiodomethane (1.20 ml, 14.9 mmol) was added to an anhydrous THF (200 ml) suspension of samarium powder (45.0 g, 299 mmol) at room temperature under nitrogen atmosphere, an anhydrous THF (700 ml) solution of diiodomethane (21.0 ml, 261 mmol) was added dropwise over 100 minutes. After the addition was completed, the reaction solution was stirred at room temperature for two hours and cooled to −78° C. An anhydrous THF (280 ml) solution of (4Z)-6-[(4-methoxybenzyl)oxy]-4-methylhexa-4-enal (28.4 g, 115 mmol) and (R)—N-bromoacetyl-4-isopropyl-2-oxazolidinone (30.1 g, 120 mmol) was added dropwise to the reaction solution at such a rate that the reaction solution temperature was kept below −72° C. After the reaction solution was stirred at −78° C. for one hour, it was warmed to room temperature. 0.5N hydrochloric acid (300 ml) to the reaction solution was added to terminate the reaction. After addition of 0.5N hydrochloric acid (700 ml), the reaction solution was extracted with ethyl acetate. After the obtained organic layer was washed with 5% sodium sulfite aqueous solution, water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate) to obtain the title compound (43.4 g, >98% de) as a yellow oil. Here, the optical purity was determined by HPLC using (DAICEL, commercial name CHIRALCEL OD; n-hexane:isopropylalcohol=4:1).
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.87 (d, J=7.2 Hz, 3H), 0.92 (d, J=7.2 Hz, 3H), 1.56-1.64 (m, 2H), 1.76 (s, 3H), 2.08-2.18 (m, 1H), 2.30-2.40 (m, 2H), 2.98 (dd, J=9.2, 16.9 Hz, 1H), 3.13 (dd, J=2.9, 16.9 Hz, 1H), 3.26 (d, J=4.4 Hz, 1H), 3.80 (s, 3H), 3.93 (dd, J=7.2, 10.8 Hz, 1H), 4.01-4.08 (m, 2H), 4.21 (dd, J=3.2, 9.2 Hz, 1H), 4.27 (t, J=9.2 Hz, 1H), 4.40-4.49 (m, 1H), 4.44 (s, 2H), 5.46 (brt, J=6.6 Hz, 1H), 6.86-6.89 (m, 2H), 7.26-7.29 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 14.55, 17.79, 23.09, 27.73, 28.34, 34.38, 42.58, 55.10, 58.25, 63.37, 65.59, 66.76, 71.75, 113.59, 122.02, 129.39, 130.26, 140.64, 153.95, 159.01, 172.18; IR (neat) 3455, 2963, 1781, 1699, 1514, 1388, 1303, 1248, 1207, 1061, 1034 cm−1; HRMS C23H34N2NaO5 (M+Na+) Calcd: 442.2206, Found: 442.2197; [α]D22−60.2 (c 1.06, CHCl3)




(2) Synthesis of methyl (3R,6Z)-3-{[tert-butyl(dimethyl)silyl]oxy}-8-[(4-methoxybenzyl)oxy]-6-methyloct-6-enoate (P4)
To a THF (175 ml) solution of (4R)-3-{(3R,6Z)-3-hydroxy-8-[(4-methoxybenzyl)oxy]-6-methyloct-6-enoyl}-4-isopropyl-1,3-oxazolidin-2-one (14.6 g, 34.8 mmol), a water (43.0 ml) solution of anhydrous lithium hydroxide (2.50 g, 104 mmol) and 30% hydrogen peroxide solution (11.8 ml) was added at 0° C. The reaction solution was stirred at room temperature for 13 hours. A water (20.0 ml) solution of anhydrous lithium hydroxide (3.75 g, 156 mmol) and 30% hydrogen peroxide solution (17.7 ml) was further added to the reaction solution and the reaction solution was stirred for two hours. After sodium sulfite (21.0 g, 165 mmol) was added to the reaction solution at 0° C., it was stirred at room temperature for five minutes. Water was added to the reaction solution and washed with chloroform. 2N hydrochloric acid was added to the water layer to acidify, which was then extracted with ethyl acetate. The organic layer was washed with water and brine sequentially and then dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure.
The obtained residue was dissolved in a mixed solvent of THF (220 ml)-methanol (22.0 ml) and cooled to 0° C. and 2M n-hexane solution of trimethylsilyldiazomethane (22.6 ml, 45.1 mmol) was added under stirring. After the reaction solution was stirred at 0° C. for 40 minutes, it was stirred at room temperature for 30 minutes. After acetic acid (1.00 ml) was added to the reaction solution and stirred at room temperature for 30 minutes, the reaction solution was concentrated under reduced pressure.
The obtained residue was dissolved in DMF (80.0 ml), followed by addition of imidazole (7.09 g, 104 mmol) and tert-butyldimethylsilyl chloride (7.85 g, 52.1 mmol), and the mixture was stirred at room temperature for 14 hours. The reaction solution was poured into water, which was then extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=6:1) to obtain the title compound (12.9 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.03 (s, 3H), 0.06 (s, 3H), 0.87 (s, 9H), 1.51-1.58 (m, 2H), 1.74 (brs, 3H), 1.96-2.05 (m, 1H), 2.08-2.18 (m, 1H), 2.39 (dd, J=5.6, 14.1 Hz, 1H), 2.46 (dd, J=7.2, 14.4 Hz, 1H), 3.66 (s, 3H), 3.80 (s, 3H), 3.96 (d, J=6.8 Hz, 2H), 4.08-4.16 (m, 1H), 4.42 (s, 2H), 5.39 (brt, J=6.8 Hz, 1H), 6.86-6.89 (m, 2H), 7.24-7.28 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −4.95, −4.63, 17.85, 23.38, 25.65, 27.50, 35.97, 42.11, 51.36, 55.10, 65.85, 69.22, 71.77, 113.65, 121.78, 129.31, 130.45, 140.24, 159.06, 171.94; IR (neat) 2952, 2930, 2856, 1740, 1514, 1250, 1083, 1038, 836, 776 cm−1; HRMS C24H41O5Si (M+H+) Calcd: 437.2723, Found: 437.2731; [α]D22−11.1 (c 1.04, CHCl3)
Step 3
Synthesis of methyl 6,7-O-benzylidene-3-O-[tert-butyl(dimethyl)silyl]-2,4,5-trideoxy-6-C-methyl-L-arabino-octonate




(1) Synthesis of methyl 3-O-[tert-butyl (dimethyl)silyl]-2,4,5-trideoxy-8-O-(4-methoxybenzyl)-6-C-methyl-L-arabino-octonate (P5)
To a mixed solution of tert-butyl alcohol (700 ml)-water (700 ml), AD-mix α (181 g) and methanesulfonamide (12.4 g, 130 mmol) were added at 0° C. and the reaction solution was stirred at 0° C. for 30 minutes. A mixed solution of tert-butyl alcohol (150 ml)-water (150 ml) of methyl (3R,6Z)-3-{[tert-butyl(dimethyl)silyl]oxy-}-8-[(4-methoxybenzyl)oxy]-6-methyloct-6-enoate (56.8 g, 130 mmol) was added to the reaction solution and stirred at 0° C. for 11 hours. Sodium sulfite (197 g, 1.56 mol) was added to the reaction solution and stirred at room temperature. After the reaction solution was diluted with water, it was extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; heptane:ethyl acetate=3:1) to obtain the title compound (56.3 g, 76% de) as a colorless oil. The optical purity was determined by HPLC using a chiral column (DAICEL, commercial name CHIRALCEL OD; n-hexane:isopropylalcohol=95:5).
400 MHz 1H-NMR (CDCl3) (data of the main product) δ (ppm) 0.04 (s, 3H), 0.06 (s, 3H), 0.86 (s, 9H), 1.17 (s, 3H), 1.24-1.40 (m, 1H), 1.46-1.68 (m, 3H), 2.39 (dd, J=5.6, 14.8 Hz, 1H), 2.45 (dd, J=6.8, 14.8 Hz, 1H), 2.66 (s, 1H), 2.73 (d, J=4.8 Hz, 1H), 3.54-3.66 (m, 3H), 3.66 (s, 3H), 3.81 (s, 3H), 4.09-4.18 (m, 1H), 4.46 (d, J=11.2 Hz, 1H), 4.50 (d, J=11.2 Hz, 1H), 6.87-6.91 (m, 2H), 7.23-7.27 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm)−4.99, −4.57, 17.85, 23.03, 25.66, 30.94, 32.86, 42.00, 51.40, 55.14, 69.40, 70.81, 73.24, 73.39, 74.78, 113.81, 129.41, 129.50, 159.32, 172.02; IR (neat) 3481, 2953, 2931, 1739, 1514, 1251, 1173, 1084, 1038, 835, 777 cm−1; HRMS C24H42NaO7Si (M+Na+) Calcd: 493.2598, Found: 493.2556; [α]D22−18.5 (c 2.22, CHCl3)




(2) Synthesis of methyl 6,7-O-benzylidene-3-O-[tert-butyl(dimethyl)silyl]-2,4,5-trideoxy-8-O-(4-methoxybenzyl)-6-C-methyl-L-arabino-octonate (P6)
To an anhydrous dichloromethane (90 ml) solution of methyl 3-O-[tert-butyl(dimethyl)silyl]-2,4,5-trideoxy-8-O-(4-methoxybenzyl)-6-C-methyl-L-arabino-octonate (5.00 g, 10.6 mmol), benzaldehyde dimethylacetal (9.55 ml, 63.6 mmol) and pyridinium p-toluene sulfonate (133 mg, 0.53 mmol) were added. The reaction solution was stirred at room temperature for 23 hours. The reaction solution was poured into a saturated sodium hydrogen carbonate aqueous solution, which was then extracted with dichloromethane. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; heptane:ethyl acetate=5:1→2:1) to obtain the title compound (5.92 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) (data of the main product) δ (ppm) 0.00 (s, 3H), 0.01 (s, 3H), 0.85 (s, 9H), 1.19-1.38 (m, 1H), 1.35 (s, 3H), 1.56-1.73 (m, 3H), 2.30 (dd, J=5.2, 14.5 Hz, 1H), 2.40 (dd, J=7.7, 14.5 Hz, 1H), 3.58 (dd, J=5.0, 9.9 Hz, 1H), 3.64 (s, 3H), 3.68 (dd, J=7.1, 9.9 Hz, 1H), 3.81 (s, 3H), 4.06 (dd, J=5.0, 7.1 Hz, 1H), 4.07-4.13 (m, 1H), 4.46 (d, J=11.4 Hz, 1H), 4.56 (d, J=11.4 Hz, 1H), 5.88 (s, 1H), 6.86-6.90 (m, 2H), 7.25-7.28 (m, 2H), 7.33-7.37 (m, 3H), 7.43-7.47 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −5.04, −4.61, 17.84, 22.73, 25.65, 30.53, 31.18, 42.18, 51.34, 55.12, 67.74, 69.47, 73.17, 81.23, 84.81, 102.27, 113.74, 126.60, 128.14, 129.02, 129.38, 129.71, 137.84, 159.23, 172.03; IR (neat) 2953, 2930, 2857, 1739, 1514, 1250, 1092, 835, 776 cm−1; HRMS C31H46NaO7Si (M+Na+) Calcd: 581.2911, Found: 581.2905; [α]D22+5.5 5 (c 1.35, CHCl3)




(3) Synthesis of methyl 6,7-O-benzylidene-3-O-[tert-butyl(dimethyl)silyl]-2,4,5-trideoxy-6-C-methyl-L-arabino-octonate (P7)
To a mixed solution of dichloromethane (176 ml)-water (17.6 ml) of methyl 6,7-O-benzylidene-3-O-[tert-butyl(dimethyl)silyl]-2,4,5-trideoxy-8-O-(4-methoxybenzyl)-6-C-methyl-L-arabino-octonate (8.80 g, 15.7 mmol), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (5.38 g, 23.7 mmol) was added at 0° C. After the reaction solution was stirred at 0° C. for one hour, water (17.6 ml) was added. After the reaction solution was stirred for two hours and a half, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (2.70 g, 11.9 mmol) was added. The reaction solution was further stirred at 0° C. for three hours. The reaction solution was poured into a sodium hydrogen carbonate aqueous solution, which was then extracted with dichloromethane. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=5:1→4:1→2:1 to obtain the title compound (4.76 g) as a white solid. The title compound (4.44 g) was obtained as a colorless crystal by recrystallization from n-hexane.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.02 (s, 3H), 0.05 (s, 3H), 0.86 (s, 9H), 1.32-1.41 (m, 1H), 1.38 (s, 3H), 1.59-1.82 (m, 3H), 1.88 (dd, J=4.0, 8.4 Hz, 1H), 2.38 (dd, J=5.6, 14.6 Hz, 1H), 2.46 (dd, J=7.2, 14.6 Hz, 1H), 3.65 (s, 3H), 3.73 (dd, J=3.6, 8.4, 11.8 Hz, 1H), 3.84 (ddd, J=4.0, 7.6, 11.8 Hz, 1H), 3.98 (dd, J=3.6, 7.6 Hz, 1H), 4.10-4.18 (m, 1H), 5.91 (s, 1H), 7.36-7.40 (m, 3H), 7.45-7.49 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm)−4.94, −4.56, 17.91, 22.66, 25.71, 30.71, 31.38, 42.25, 51.47, 61.42, 69.40, 81.33, 86.38, 102.20, 126.60, 128.36, 129.29, 137.69, 172.07; IR (KBr) 3489, 2951, 2856, 1746, 1087, 1024, 836, 768, 704 cm−1; HRMS C23H38NaO6Si (M+Na+) Calcd: 461.2335, Found: 461.2368; [α]D22−4.31 (c 1.21, CHCl3)
Step 4
Synthesis of (3R)-3-{[tert-butyl (dimethyl)silyl]oxy}-5-[(2S,4R,5S)-4-methyl-2-phenyl-5-vinyl-1,3-dioxolan-4-yl]pentanoic acid




(1) Synthesis of methyl (3R)-3-{[tert-butyl(dimethyl)silyl]oxy}-5-[(2S,4R,5S)-4-methyl-2-phenyl-5-vinyl-1,3-dioxolan-4-yl] pentanoate (P8)
To a dichloromethane (300 ml) solution of methyl 6,7-O-benzylidene-3-O-[tert-butyl(dimethyl)silyl]-2,4,5-trideoxy-6-C-methyl-L-arabino-octonate (10.2 g, 23.3 mmol), Dess-Martin reagent (12.8 g, 30.3 mmol) was added. The reaction solution was stirred at room temperature for one hour. The reaction solution was diluted with ether and washed with a saturated sodium hydrogen carbonate aqueous solution containing sodium sulfite and brine sequentially. The organic layer was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure.
The obtained residue was dissolved in anhydrous THF (50.0 ml) and this solution was added dropwise at −15° C. to an anhydrous THF (100 ml) solution of methylenetriphenylphosphorane prepared by a conventional method from methyltriphenylphosphonium iodide (10.4 g, 25.7 mmol) and n-butyllithium (2.59M n-hexane solution 9.94 ml, 25.7 mmol) under nitrogen atmosphere. After the reaction solution was stirred at −15° C. for 20 minutes, it was stirred at room temperature for 30 minutes. The reaction solution was poured into a saturated ammonium chloride aqueous solution, which was then extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=19:1→9:1) to obtain the title compound (7.91 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.00 (s, 3H), 0.02 (s, 3H), 0.85 (s, 9H), 1.25-1.36 (m, 1H), 1.35 (s, 3H), 1.55-1.72 (m, 3H), 2.34 (dd, J=5.4, 14.6 Hz, 1H), 2.42 (dd, J=7.4, 14.6 Hz, 1H), 3.64 (s, 3H), 4.06-4.14 (m, 1H), 4.28 (ddd, J=1.2, 1.2, 6.8 Hz, 1H), 5.31 (ddd, J=1.2, 1.2, 10.6 Hz, 1H), 5.42 (ddd, J=1.2, 1.2, 17.2 Hz, 1H), 5.90 (ddd, J=6.8, 10.6, 17.2 Hz, 1H), 5.92 (s, 1H), 7.35-7.38 (m, 3H), 7.46-7.50 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −5.05, −4.66, 17.81, 22.36, 25.63, 31.30, 31.93, 42.23, 51.28, 69.50, 82.14, 87.73, 102.12, 118.69, 126.57, 128.15, 128.99, 132.58, 137.90, 171.98; IR (neat) 2954, 2930, 2857, 1740, 1255, 1090, 1065, 1006, 836, 776 cm−1; HRMS C24H38NaO5Si (M+Na+) Calcd: 457.2386, Found: 457.2394; [α]D22−11.5 (c 2.26, CHCl3)




(2) Synthesis of (3R)-3-{[tert-butyl(dimethyl)silyl]oxy}-5-[(2S,4R,5S)-4-methyl-2-phenyl-5-vinyl-1,3-dioxolan-4-yl]pentanoic acid (P9)
Methyl (3R)-3-{[tert-butyl(dimethyl)silyl]oxy}-5-[(2S,4R,5S)-4-methyl-2-phenyl-5-vinyl-1,3-dioxolan-4-yl]pentanoate (14.6 g, 33.6 mmol) was dissolved in a mixed solution of THF (140 ml)-methanol (140 ml)-water (70.0 ml) and anhydrous lithium hydroxide (4.02 g, 168 mmol) was added. The reaction solution was stirred at room temperature for four and a half hours. The reaction solution was poured into 0.5N hydrochloric acid, which was then extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=4:1→2:1) to obtain the title compound (14.1 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.05 (s, 6H), 0.87 (s, 9H), 1.26-1.34 (m, 1H), 1.35 (s, 3H), 1.50-1.68 (m, 2H), 1.73-1.79 (m, 1H), 2.44 (dd, J=5.4, 15.4 Hz, 1H), 2.48 (dd, J=5.4, 15.4 Hz, 1H), 4.00-4.06 (m, 1H), 4.29 (ddd, J=1.2, 1.2, 6.8 Hz, 1H), 5.32 (ddd, J=1.2, 1.2, 10.1 Hz, 1H), 5.44 (ddd, J=1.2, 1.2, 17.2 Hz, 1H), 5.88 (ddd, J=6.8, 10.8, 17.2 Hz, 1H), 5.93 (s, 1H), 7.35-7.38 (m, 3H), 7.47-7.49 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −5.00, −4.63, 17.88, 22.38, 25.69, 31.18, 32.03, 41.99, 69.40, 82.18, 87.77, 102.17, 118.88, 126.59, 128.25, 129.10, 132.51, 137.90, 177.39; IR (neat) 3036, 2956, 2930, 2886, 2857, 1712, 1254, 1090, 1065, 836, 776 cm−1; HRMS C23H36NaO5Si (M+Na+) Calcd: 443.2230, Found: 443.2212; [α]D22+4.00 (c 1.09, CHCl3)
Step 5
Synthesis of (2E)-4-[(4-methoxybenzyl)oxy]-2-methylbut-2-enal




(1) Synthesis of 1-({[(2E)-4,4-dimethoxy-3-methylbut-2-en-1-yl]oxy}methyl)-4-methoxybenzene (P10)
Sodium hydride (60%, 407 mg, 10.2 mmol) was added to an anhydrous THF (20.0 ml) solution of triethyl phosphonoacetate (2.28 g, 10.2 mmol) at 0° C. under nitrogen atmosphere. After the reaction solution was stirred at 0° C. for 15 minutes, pyruvaldehyde dimethylacetal (1.00 g, 8.47 mmol) was added. After the reaction solution was stirred at 0° C. for 30 minutes, it was stirred at room temperature for 10 minutes. The reaction solution was poured into water, which was then extracted with n-hexane. After the organic layer was washed with brine, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure.
The obtained residue was dissolved in anhydrous THF (32.0 ml) and cooled to −78° C. under nitrogen atmosphere. Diisobutylaluminum hydride 0.95M toluene solution (21.3 ml, 20.3 mmol) was added dropwise to this solution. After the reaction solution was stirred at −78° C. for 10 minutes, it was stirred at room temperature for 30 minutes. After the reaction solution was ice cooled, followed by addition of 20% Rochelle salt solution, and vigorously stirred for one hour, it was extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure.
The obtained residue was dissolved in dimethoxyethane (12.0 ml) and cooled to 0° C. under nitrogen atmosphere. After addition of sodium hydride (60%, 394 mg, 9.85 mmol) to this solution and stirring at 0° C. for 20 minutes, p-methoxybenzyl chloride (1.00 ml, 7.39 mmol) and sodium iodide (1.11 g, 7.39 mmol) were added. After the reaction solution was stirred at room temperature for 45 minutes, it was poured into water, which was then extracted with n-hexane. After the organic layer was washed with a sodium sulfite aqueous solution and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; heptane:ethyl acetate=19:1→9:1→5:1) to obtain the title compound (1.52 g) as a colorless oil. The title compound was determined to be a mixture of E:Z=18:7 by 1H-NMR.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.62 (d, J=0.8 Hz, 2.16H), 1.74 (d, J=1.2 Hz, 0.84H), 3.30 (s, 1.68H), 3.31 (s, 4.32H), 3.81 (s, 2.16H), 3.82 (s, 0.84H), 4.09 (d, J=6, 0 Hz, 2H), 4.45 (s, 2H), 4.49 (s, 0.72H), 4.87 (s, 0.28H), 5.66 (brt, J=6.6 Hz, 0.28H), 5.78 (brt, J=6.2 Hz, 0.72H), 6.86-6.91 (m, 2H), 7.25-7.28 (m, 2H); IR (neat) 2934, 2834, 1514, 1249, 1112, 1072, 1036, 820 cm−1; HRMS C15H22AgO4 (M+Ag+) Calcd: 373.0569, Found: 373.0552




(2) Synthesis of (2E)-4-[(4-methoxybenzyl)oxy]-2-methylbut-2-enal (P11)
1-({[(2E)-4,4-dimethoxy-3-methylbut-2-en-1-yl]oxy}methyl)-4-methoxybenzene (1.52 g, 5.71 mmol) was dissolved in acetonitrile (16.0 ml), followed by addition of 1N hydrochloric acid (4.00 ml) and the reaction solution was stirred at room temperature for one hour. Subsequently, 2N hydrochloric acid (4.00 ml) to the reaction solution was added and it was further stirred for four hours. The reaction solution was poured into a saturated aqueous solution of sodium hydrogen carbonate, which was then extracted with diethyl ether. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. The drying agent was filtered off and the organic layer was concentrated under reduced pressure to obtain the title compound (1.52 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.73 (dt, J=1.2, 1.2 Hz, 3H), 3.82 (s, 3H), 4.32 (dq, J=1.2, 5.6 Hz, 2H), 4.52 (s, 2H), 6.60 (tq, J=1.2, 5.6 Hz, 1H), 6.88-6.92 (m, 2H), 7.26-7.30 (m, 2H), 9.44 (s, 1H); 100 MHz 13C-NMR (CDCl3 δ (ppm) 9.20, 54.94, 66.17, 72.45, 113.63, 129.24, 129.32, 139.04, 149.47, 159.18, 194.10; IR (neat) 2837, 1688, 1612, 1512, 1249, 1074, 1033, 820 cm−1; HRMS C13H16NaO3 (M+Na+) Calcd: 243.0997, Found: 243.1044
Step 6
Synthesis of (1S,3R,4S,5E)-4-{[tert-butyl(dimethyl)silyl]oxy}-7-[(4-methoxybenzyl)oxy]-1,3,5-trimethyl-2-oxohept-5-en-1-yl benzoate




(1) Synthesis of (1S,3R,4S,5E)-4-hydroxy-7-[(4-methoxybenzyl)oxy]-1,3,5-trimethyl-2-oxohept-5-en-1-yl benzoate (P12)
This reaction was performed with reference to the literature (Paterson, I.; Wallac, D.; Cowden, C. J.; Synthesis, 1998, 639-652.). (S)-2-benzoyloxypentane-3-one used in this step was prepared by a method described in this literature.
Anhydrous diethyl ether distilled by using lithium aluminum hydride immediately before use was used in this step.
N,N-dimethylethylamine (24.0 ml, 221 mmol) was added to an anhydrous diethyl ether (500 ml) solution of dicyclohexylboron chloride (38.8 ml, 177 mmol) prepared from a commercial boron monochrolide-methyl sulfide complex by a method described in the literature (Paterson, I.; Temal-Laib, T.; Org. Lett., 2002, 4(15), 2473-2476.) under nitrogen atmosphere −78° C. and the reaction solution was stirred at −78° C. for 15 minutes. An anhydrous diethyl ether (400 ml) solution of (S)-2-benzoyloxy pentane-3-one (30.4 g, 148 mmol) was added dropwise to this reaction solution over 35 minutes, and it was stirred at −78° C. for 10 minutes and then stirred at 0° C. for two hours. The reaction solution was cooled to −78° C. again and an anhydrous diethyl ether (400 ml) solution of (2E)-4-[(4-methoxybenzyl)oxy]-2-methylbut-2-enal (27.0 g, 123 mmol) was added dropwise over 20 minutes and it was stirred at −78° C. for two hours and then stirred at −26° C. overnight. After the reaction solution was warmed to 0° C., methanol (400 ml), phosphate buffer (pH=7, 400 ml) and 30% hydrogen peroxide solution (350 ml) were added sequentially and the reaction solution was stirred at 0° C. for one hour. The reaction solution was poured into water, which was then extracted with ethyl acetate. The organic layer was washed with water and brine sequentially and dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=4:1→2:1). The obtained white solid was recrystallized (n-hexane:ethyl acetate) to obtain the title compound (42.6 g, >99% de) as a colorless needle. The optical purity was determined by HPLC using a chiral column (DAICEL, commercial name CHIRALCEL OD; n-hexane:isopropylalcohol=95:5).
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.07 (d, J=7.2 Hz, 3H), 1.57 (d, J=7.2 Hz, 3H), 1.63 (s, 3H), 2.02 (d, J=3.8 Hz, 1H), 3.04 (dq, J=7.2, 9.2 Hz, 1H), 3.81 (s, 3H), 3.80-4.10 (m, 2H), 4.24 (dd, J=3.8, 9.2 Hz, 1H), 4.44 (s, 2H), 5.45 (q, J=7.2 Hz, 1H), 5.65 (brt, J=6.4 Hz, 1H), 6.86-6.90 (m, 2H), 7.24-7.28 (m, 2H), 7.44-7.47 (m, 2H), 7.56-7.61 (m, 1H), 8.07-8.10 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 11.07, 14.46, 15.46, 45.38, 55.22, 65.75, 72.00, 75.06, 79.48, 113.75, 126.06, 128.38, 129.36, 129.51, 129.74, 130.20, 133.23, 138.19, 159.18, 165.83, 210.72; IR (KBr) 3466, 3050, 2991, 2967, 2932, 2871, 2836, 1731, 1719, 1513, 1453, 1301, 1247, 1121, 1072, 1038, 996, 711 cm−1; HRMS C25H30NaO6 (M+Na+) Calcd: 449.1940, Found: 449.1951, [α]D25 +30.3 (c 1.00, CHCl3)




(2) Synthesis of (1S,3R,4S,5E)-4-{[tert-butyl(dimethyl)silyl]oxy}-7-[(4-methoxybenzyl)oxy]-1,3,5-trimethyl-2-oxohept-5-en-1-yl benzoate (P13)
2,6-Lutidine (38.2 ml, 328 mmol) was added to an anhydrous dichloromethane (1.00 l) solution of (1S,3R,4S,5E)-4-hydroxy-7-[(4-methoxybenzyl)oxy]-1,3,5-trimethyl-2-oxohept-5-en-1-yl benzoate (70.0 g, 164 mmol) at −78° C. under nitrogen atmosphere. Trifluoromethanesulfonic acid tert-butyldimethylsilyl ester (56.5 ml, 246 mmol) was added dropwise to the reaction solution over 10 minutes. After the reaction solution was stirred at −78° C. for one and a half hour, a saturated sodium hydrogen carbonate aqueous solution was added at −78° C. The reaction solution was warmed to room temperature, which was then extracted with dichloromethane. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=8:1) to obtain the title compound (89.0 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) −0.02 (s, 3H), −0.01 (s, 3H), 0.82 (s, 9H), 0.97 (d, J=7.2 Hz, 3H), 1.54 (d, J=7.2 Hz, 3H), 1.58 (s, 3H), 3.00 (dq, J=7.2, 9.6 Hz, 1H), 3.81 (s, 3H), 4.04 (d, J=6.0 Hz, 2H), 4.28 (d, J=9.6 Hz, 1H), 4.43 (s, 2H), 5.43 (q, J=7.2 Hz, 1H), 5.59 (brt, J=6.0 Hz, 1H), 6.86-6.90 (m, 2H), 7.24-7.27 (m, 2H), 7.43-7.47 (m, 2H), 7.56-7.60 (m, 1H), 8.07-8.09 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −5.17, −4.78, 10.79, 14.54, 15.17, 18.01, 25.75, 46.17, 55.21, 65.83, 71.72, 75.20, 80.54, 113.75, 126.24, 128.36, 129.22, 129.66, 129.76, 130.35, 133.16, 138.11, 159.15, 165.68, 209.02; IR (neat) 2954, 2931, 2856, 1721, 1512, 1453, 1301, 1250, 1117, 1070, 1040, 837, 778, 713 cm−1; HRMS C31H44NaO6Si (M+Na+) Calcd: 563.2805, Found: 563.2786; [α]D25 +12.6 (c 1.01, CHCl3)
Step 7
(3S,4S,5E)-7-[(4-methoxybenzyl)oxy]-3,5-dimethylhepta-1,5-dien-4-ol




(1) Synthesis of tert-butyl({(1S,2E)-4-[(4-methoxybenzyl)oxy]-2-methyl-1-[(1S)-1-methylprop-2-en-1-yl]but-2-en-1-yl}oxy)dimethylsilane (P14)
To an anhydrous THF (10.0 ml) solution of (1S,3R,4S,5E)-4-{[tert-butyl(dimethyl)silyl]oxy}-7-[(4-methoxybenzyl)oxy]-1,3,5-trimethyl-2-oxohept-5-en-1-yl benzoate (1.00 g, 1.85 mmol), lithium boron hydride 2M THF (18.5 ml, 37.0 mmol) solution was added at −78° C. under nitrogen atmosphere. The reaction solution was stirred overnight while warmed to room temperature. After the reaction solution was ice cooled and water was added thereto, it was extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. The drying agent was filtered off and the organic layer was concentrated under reduced pressure to obtain a white solid (611 mg).
300 mg from the obtained white solid was dissolved in a mixed solvent of THF-water (4:1, 6.00 ml). Sodium periodate (438 mg, 2.05 mmol) was added to the reaction solution. After the reaction solution was stirred to at room temperature for one and a half hour, it was poured into water, which was then extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure.
The obtained residue was dissolved in anhydrous THF (4.00 ml) and added dropwise at under nitrogen atmosphere at −15° C. to an anhydrous THF (4.00 ml) solution of methylenetriphenylphosphorane prepared by a conventional method from methyl iodide triphenylphosphonium (415 mg, 1.02 mmol) and 2.59M n-butyllithium n-hexane (397 μl, 1.03 mmol) solution. After the reaction solution was stirred at −15° C. for one hour, it was poured into water, which was then extracted with ethyl acetate. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=19:1) to obtain the title compound (258 mg) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) −0.03 (s, 3H), 0.02 (s, 3H), 0.87 (d, J=7.2 Hz, 3H), 0.88 (s, 9H), 1.58 (s, 3H), 2.24-2.33 (m, 1H), 3.72 (d, J=7.2 Hz, 1H), 3.81 (s, 3H), 4.05 (d, J=6.4 Hz, 2H), 4.42 (s, 2H), 4.98 (brd, J=10.4 Hz, 1H), 4.99 (brd, J=17.4 Hz, 1H), 5.50 (brt, J=6.4 Hz, 1H), 5.84 (ddd, J=7.6, 10.4, 17.4 Hz, 1H), 6.87-6.89 (m, 2H), 7.25-7.27 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −5.02, −4.55, 11.74, 16.65, 18.16, 25.81, 42.07, 55.12, 65.84, 71.32, 82.35, 113.68, 113.91, 123.76, 129.19, 130.55, 140.26, 141.67, 159.07; IR (neat) 2956, 2929, 2856, 1514, 1249, 1065, 1040, 836, 775 cm−1; HRMS C23H38NaO3Si (M+Na+) Calcd: 413.2488, Found: 413.2504; [α]D26 −2.26 (c 1.02, CHCl3)




(2) Synthesis of (3S,4S,5E)-7-[(4-methoxybenzyl)oxy]-3,5-dimethylhepta-1,5-dien-4-ol (P15)
1N hydrochloric acid (100 ml) was added to an acetonitrile (300 ml) solution of tert-butyl({(1S,2E)-4-[(4-methoxybenzyl)oxy]-2-methyl-1-[(1S)-1-methylprop-2-en-1-yl]but-2-en-1-yl}oxy)dimethylsilane (41.8 g, 107 mmol). After the reaction solution was stirred at room temperature for ten and a half hours, it was poured into brine and extracted with ethyl acetate. After the organic layer was washed with brine, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=4:1→3:1→2:1) and was obtained title compound (26.8 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.93 (d, J=6.4 Hz, 3H), 1.64 (s, 3H), 1.77 (brs, 1H), 2.28-2.39 (m, 1H), 3.71 (d, J=8.0 Hz, 1H), 3.81 (s, 3H), 4.07 (d, J=6.4 Hz, 2H), 4.45 (s, 2H), 5.15 (brd, J=10.4 Hz, 1H), 5.16 (brd, J=17.1 Hz, 1H), 5.62 (brt, J=6.4 Hz, 1H), 5.75 (ddd, J=8.4, 10.4, 17.1 Hz, 1H), 6.86-6.90 (m, 2H), 7.25-7.29 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 11.44, 16.62, 41.60, 55.04, 65.74, 71.58, 80.52, 113.59, 116.10, 124.73, 129.19, 130.24, 138.94, 140.67, 159.00; IR (neat) 3443, 2962, 2931, 2862, 1613, 1513, 1456, 1301, 1249, 1174, 1065, 1035, 913, 820 cm−1; HRMS C17H24NaO3 (M+Na+) Calcd: 299.1623, Found: 299.1612; [α]D26 −14.1 (c 1.02, CHCl3)
Step 8
Synthesis of (2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl (dimethyl)silyl]oxy}-7-{(1E)-3-[(4-methoxybenzyl)oxy]-1-methylprop-1-en-1-yl}-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one




(1) Synthesis of (1S,2E)-4-[(4-methoxybenzyl)oxy]-2-methyl-1-[(1S)-1-methylprop-2-en-1-yl]but-2-en-1-yl 3-{[tert-butyl(dimethyl)silyl]oxy}-5-[(2S,4R,5S)-4-methyl-2-phenyl-5-vinyl-1,3-dioxolan-4-yl]pentanoate (P16)
This reaction was performed with reference to the literature (Inanaga, J.; Hirata, K.; Saeki, H; Katsuki, T.; Yamaguchi, M.; Bull. Chem. Soc. Jpn. 1979, 52(7), 1989-1993.).
To an anhydrous THF (130 ml) solution of (3R)-3-{[tert-butyl(dimethyl)silyl]oxy}-5-[(2S,4R,5S)-4-methyl-2-phenyl-5-vinyl-1,3-dioxolan-4-yl] pentanoic acid (6.50 g, 15.5 mmol) was added triethylamine (2.80 ml, 20.2 mmol) under nitrogen atmosphere and cooled to 0° C. 2,4,6-Trichlorobenzoyl chloride (2.65 ml, 17.0 mmol) was added to the reaction solution. After the reaction solution was stirred at 0° C. for 10 minutes, it was stirred at room temperature for two hours. After the reaction solution was filtered with celite, the organic layer was concentrated under reduced pressure. To the obtained residue, an anhydrous toluene (130 ml) solution of (3S,4S,5E)-7-[(4-methoxybenzyl)oxy]-3,5-dimethylhepta-1,5-dien-4-ol (4.71 g, 17.0 mmol) and 4-dimethylaminopyridine (2.46 g, 20.2 mmol) were added under nitrogen atmosphere. After the reaction solution was stirred at room temperature for two hours, it was poured into 0.5N hydrochloric acid and extracted with ethyl acetate. After the organic layer was washed with a saturated sodium hydrogen carbonate aqueous solution, water and brine sequentially, it was dried over magnesium sulfate anhydrous. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=10:1→5:1) to obtain the title compound (9.81 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.01 (s, 3H), 0.02 (s, 3H), 0.86 (s, 9H), 0.94 (d, J=6.8 Hz, 3H), 1.22-1.32 (m, 1H), 1.32 (s, 3H), 1.57-1.65 (m, 2H), 1.60 (s, 3H), 1.65-1.79 (m, 1H), 2.32 (dd, J=6.0, 15.2 Hz, 1H), 2.43 (dd, J=6.0, 15.2 Hz, 1H), 2.42-2.52 (m, 1H), 3.80 (s, 3H), 4.02 (d, J=6.4 Hz, 2H), 4.01-4.08 (m, 1H), 4.26 (dt, J=1.0, 7.0 Hz, 1H), 4.40 (s, 2H), 4.96-5.05 (m, 3H), 5.29 (ddd, J=1.0, 1.6, 10.5 Hz, 1H), 5.41 (dt, J=1.6, 17.5 Hz, 1H), 5.62 (brt, J=6.2 Hz, 1H), 5.69 (ddd, J=8.0, 10.4, 17.2 Hz, 1H), 5.88 (ddd, J=7.0, 10.5, 17.5 Hz, 1H), 5.90 (s, 1H), 6.85-6.89 (m, 2H), 7.23-7.26 (m, 2H), 7.26-7.37 (m, 3H), 7.48-7.52 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −4.83, −4.76, 12.65, 16.63, 17.85, 22.32, 25.73, 31.21, 32.28, 39.94, 42.72, 55.09, 65.60, 69.21, 71.53, 81.37, 82.18, 87.72, 102.16, 113.65, 115.17, 118.64, 126.03, 126.67, 128.14, 129.00, 129.27, 130.25, 132.66, 135.33, 137.90, 139.83, 159.08, 170.36; IR (neat) 2957, 2931, 2856, 1736, 1612, 1250, 1173, 1090, 1065, 1036, 836 cm−1; HRMS C40H58NaO7Si (M+Na+) Calcd: 701.3849, Found: 701.3824; [α]D23 −2.69 (c 1.09, CHCl3)




(2) Synthesis of (2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-{(1E)-3-[(4-methoxybenzyl)oxy]-1-methylprop-1-en-1-yl}-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (P17)
Anhydrous toluene distilled by using benzophenone ketyl immediately before use under Ar atmosphere was used in this step.
(1S,2E)-4-[(4-methoxybenzyl)oxy]-2-methyl-1-[(1S)-1-methylprop-2-en-1-yl]but-2-en-1-yl 3-{[tert-butyl(dimethyl)silyl]oxy}-5-[(2S,4R,5S)-4-methyl-2-phenyl-5-vinyl-1,3-dioxolan-4-yl]pentanoate (1.10 g, 1.63 mmol) and 2,6-di-tert-butyl-4-methylphenol (35.9 mg, 0.16 mmol) were dissolved in anhydrous toluene under Ar atmosphere. The reaction solution was heated to reflux for one hour. An anhydrous toluene (330 ml) solution of the second generation Hoveyda-Grubbs catalyst; [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium (102 mg, 0.16 mmol) was added to the reaction solution. After the reaction solution was heated to reflux for five hours, it was cooled to room temperature. The reaction solution was filtered with silica gel (Fuji Silysia, commercial name Chromatorex, NH, 200-350 mesh) and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=8:1) to obtain the title compound (486.1 mg) as a white solid. This was obtained as a colorless needle by recrystallization (hexane:ethyl acetate).
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.07 (s, 3H), 0.09 (s, 3H), 0.88 (s, 9H), 0.91 (d, J=6.8 Hz, 3H), 1.38 (s, 3H), 1.38-1.46 (m, 1H), 1.48-1.56 (m, 1H), 1.61 (s, 3H), 1.62-1.68 (m, 1H), 1.99-2.10 (m, 1H), 2.31 (dd, J=10.4, 14.7 Hz, 1H), 2.52-2.58 (m, 1H), 2.58 (dd, J=4.4, 14.7 Hz, 1H), 3.81 (s, 3H), 3.92-4.01 (m, 1H), 4.04 (d, J=6.4 Hz, 2H), 4.19 (d, J=9.4 Hz, 1H) 4.42 (s, 2H), 4.97 (d, J=10.8 Hz, 1H), 5.41 (dd, J=9.8, 15.2 Hz, 1H), 5.63 (dd, J=9.4, 15.2 Hz, 1H), 5.74 (brt, J=6.4 Hz, 1H), 5.91 (s, 1H), 6.87-6.90 (m, 2H), 7.24-7.26 (m, 2H), 7.36-7.40 (m, 3H), 7.49-7.51 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −4.73, −4.61, 11.50, 16.72, 17.80, 22.69, 25.62, 31.44, 34.31, 39.97, 43.98, 55.02, 65.45, 71.51, 71.69, 81.55, 83.44, 85.18, 101.07, 113.61, 126.62, 128.18, 128.41, 129.12, 129.21, 129.47, 130.05, 134.39, 137.55, 137.63, 159.05, 168.89; IR (neat) 2932, 2856, 1735, 1513, 1460, 1247, 1066, 1034, 1006, 978, 836 cm−1; HRMS C38H54NaO7Si (M+Na+) Calcd: 673.3536, Found: 673.3505; [α]D28 −14.8 (c 1.03, CHCl3)
Step 9
Synthesis of (2E)-3-((2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl (dimethyl)silyl]oxy}-6,13a-dimethyl-9-oxo-2-phenyl-6,7,9,10,11,12,13,13a-octahydro-3aH-[1,3]dioxolo[4,5-f]oxacyclododecin-7-yl)but-2-enal




(1) Synthesis of (2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-{(1E)-3-hydroxy-1-methylprop-1-en-1-yl}-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (P18)
(2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-{(1E)-3-[(4-methoxybenzyl)oxy]-1-methylprop-1-en-1-yl}-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (710 mg, 1.09 mmol) was dissolved in dichloromethane (14.0 ml) and a phosphate buffer (pH=7, 1.40 ml). 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (297 mg, 1.31 mmol) was added to the reaction solution at 0° C. and stirred for three hours. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (74.3 mg, 0.33 mmol) was added and the reaction solution was stirred at 0° C. for one and a half hour. After 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (74.3 mg, 0.33 mmol) was added and the reaction solution was stirred at 0° C. for further 30 minutes, the reaction solution was filtered with silica gel (Fuji Silysia, commercial name Chromatorex, NH, 200-350 mesh). The filtrate was washed with a saturated sodium hydrogen carbonate aqueous solution, distilled water and brine sequentially and dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=4:1→3:1) to obtain the title compound (460 mg) as a colorless needle.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.08 (s, 3H), 0.09 (s, 3H), 0.88 (s, 9H), 0.90 (d, J=6.8 Hz, 3H), 1.25 (t, J=5.6 Hz, 1H), 1.38-1.46 (m, 2H), 1.39 (s, 3H), 1.60-1.68 (m, 1H), 1.65 (s, 3H), 2.00-2.09 (m, 1H), 2.32 (dd, J=10.2, 14.6 Hz, 1H), 2.52-2.59 (m, 1H), 2.59 (dd, J=4.2, 14.6 Hz, 1H), 3.92-4.01 (m, 1H), 4.16-4.27 (m, 3H), 4.95 (d, J=10.4 Hz, 1H), 5.41 (dd, J=9.8, 15.2 Hz, 1H), 5.64 (dd, J=9.6, 15.2 Hz, 1H), 5.75 (brt, J=5.8 Hz, 1H), 5.91 (s, 1H), 7.36-7.41 (m, 3H), 7.49-7.52 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −4.67, −4.56, 11.24, 16.69, 17.88, 22.75, 25.67, 31.50, 34.33, 39.92, 43.98, 58.64, 71.49, 81.86, 83.55, 85.25, 101.15, 126.70, 128.28, 129.25, 129.56, 130.77, 133.52, 137.58, 169.25; IR (KBr) 3232, 2937, 2858, 1730, 1243, 1107, 1082, 1067, 1007, 973, 836, 776, 700 cm−1; HRMS C30H46NaO6Si (M+Na+) Calcd: 553.2961, Found: 553.2948; [α]D23 −11.5 (c 1.02, CHCl3)




(2) Synthesis of (2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-[(E)-2-formyl-1-methyleth-1-en-1-yl]-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (P19)
Dess-Martin reagent (565 mg, 1.33 mmol) was added to a dichloromethane (12.0 ml) solution of (2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-{(1E)-3-hydroxy-1-methylprop-1-en-1-yl}-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (587 mg, 1.11 mmol). The reaction solution was stirred at room temperature for 30 minutes. The reaction solution was diluted with ether and washed with a saturated sodium hydrogen carbonate aqueous solution containing sodium sulfite, water and brine sequentially and dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=10:1→8:1→6:1) to obtain the title compound (587 mg) as a white solid. This was obtained as a colorless crystal by recrystallization (hexane:ethyl acetate).
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.09 (s, 3H), 0.10 (s, 3H), 0.89 (s, 9H), 0.95 (d, J=6.8 Hz, 3H), 1.38-1.50 (m, 2H), 1.40 (s, 3H), 1.63-1.70 (m, 1H), 1.96-2.10 (m, 1H), 2.17 (d, J=1.2 Hz, 3H), 2.37 (dd, J=9.6, 14.4 Hz, 1H), 2.60 (dd, J=4.0, 14.4 Hz, 1H), 2.61 (m, 1H), 3.93-4.03 (m, 1H), 4.20 (d, J=9.6 Hz, 1H), 4.92 (d, J=10.4 Hz, 1H), 5.41 (dd, J=9.2, 15.2 Hz, 1H), 5.69 (dd, J=9.6, 15.2 Hz, 1H), 5.92 (s, 1H), 6.07 (dd, J=1.2, 7.6 Hz, 1H), 7.34-7.42 (m, 3H), 7.48-7.52 (m, 2H), 10.0 (d, J=7.6 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −4.70, −4.60, 13.20, 16.31, 17.87, 22.66, 25.64, 31.46, 34.14, 40.40, 43.19, 71.13, 80.52, 83.52, 85.00, 101.22, 126.63, 128.28, 129.25, 129.84, 130.58, 136.19, 137.59, 155.92, 168.80, 190.56; IR (KBr) 2954, 2935, 2880, 2858, 2787, 2755, 1739, 1674, 1461, 1401, 1240, 1224, 1101, 1004, 980, 830, 775, 698 cm−1; HRMS C30H44NaO6Si (M+Na+) Calcd: 551.2805, Found: 551.2803; [α]D27 +4.00 (c 1.06, CHCl3)
Step 10
Synthesis of (3S)-4-(benzyloxy)-3-methylbutan-1-ol




(1) Synthesis of methyl (2R)-3-(benzyloxy)-2-methylpropanoate (P20)
This reaction was performed with reference to the literature (Widmer, U.; Synthesis, 1987, 568-570.).
Methyl (R)-3-hydroxy-isobutyrate (6.30 g, 53.3 mmol) was dissolved in a mixed solution (180 ml) of dichloromethane-cyclohexane (1:1), followed by addition of benzyl-2,2,2-trichloroacetimidate (12.0 ml, 64.6 mmol) at room temperature. After trifluoromethanesulfonic acid (0.80 ml, 5.40 mmol) was added dropwise to this, the reaction solution was stirred at room temperature for three hours. After the reaction solution was diluted with dichloromethane, it was washed with a sodium hydrogen carbonate aqueous solution and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=30:1) and the title compound (9.79 g) was obtained as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.19 (d, J=7.2 Hz, 3H), 2.74-2.84 (m, 1H), 3.50 (dd, J=6.0, 9.2 Hz, 1H), 3.66 (dd, J=7.2, 9.2 Hz, 1H), 3.69 (s, 3H), 4.52 (s, 2H), 7.20-7.37 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 13.91, 40.12, 51.65, 71.89, 73.02, 127.51, 127.53, 128.28, 138.09, 175.24; IR (neat) 2977, 2946, 2862, 2362, 2323, 1738, 1458, 1202 cm−1; HRMS C12H16NaO3 (M+Na+) Calcd: 231.0997, Found: 231.0989; [α]D28 −10.9 (c 2.10, CHCl3)




(2) Synthesis of ({[(2S)-4-methoxy-2-methylbut-3-en-1-yl]oxy}methyl)benzene (P21)
This reaction was performed with reference to the literature (Rich, D. H.; Sun, E. T.; Boparai, A. S.; J. Org. Chem., 1978, 43(18) 3624-3626. Feng, X.; Edstrom, E. D., Tetrahedron Asymmetry, 1999, 10(1), 99-105. Gibson, S. E.; Guillo, N.; Middleton, R. J.; Thuilliez, A.; Tozer, M. J.; J. Chem. Soc. Perkin Trans., 1997, 1, 447-455.).
1.0M diisobutylaluminum hydride toluene solution (3.78 ml) was added dropwise to a toluene (32 ml) solution of methyl (2R)-3-(benzyloxy)-2-methylpropanoate (0.81 g, 3.88 mmol) at −78° C. and the reaction solution was stirred at the same temperature for 1.5 hours. After addition of methanol (0.5 ml, 12.3 mmol), the reaction solution was warmed to room temperature. The reaction solution was stirred for further two hours. The reaction solution was filtered through celite and the filtrate was dried over sodium sulfate. The drying agent was filtered off, the solvent was evaporated under reduced pressure and aldehyde was obtained as a crude product.
After potassium tert-butoxide (0.76 g, 6.76 mmol) was added to a THF (20 ml) solution of (methoxymethyl)triphenylphosphonium chloride (2.54 g, 7.40 mmol) while ice cooling, the mixture was stirred at room temperature for 30 minutes. Subsequently a THF (5 ml) solution of the above aldehyde was added dropwise to this reaction solution at room temperature and stirred for 12 hours. After the reaction solution was diluted with ethyl acetate, it was washed with water and brine. After the organic layer was dried over anhydrous magnesium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=100:1) to obtain the title compound (0.44 g) as a colorless oil. Title compound was determined to be a mixture of E:Z=2:1 by 1H-NMR.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.01 (d, J=6.8 Hz, 0.9H), 1.04 (d, J=6.8 Hz, 2.1H), 2.36-2.47 (m, 0.7H), 2.92-3.00 (m, 0.3H), 3.22-3.37 (m, 2H), 3.50 (s, 2.1H), 3.58 (s, 0.9H), 4.23 (dd, J=6.4, 9.2 Hz, 0.3H), 4.52 (s, 2.0H), 4.65 (dd, J=8.0, 12.8 Hz, 0.7H), 5.89 (dd, J=0.8, 6.4 Hz, 0.3H), 6.35 (dd, J=0.8, 12.8 Hz, 0.7H), 7.25-7.36 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 17.97, 18.43, 29.60, 33.22, 55.67, 59.50, 72.67, 72.88, 75.24, 76.16, 105.60, 109.51, 127.34, 127.45, 127.53, 128.25, 128.31, 138.72, 138.92, 146.35, 147.31; IR (neat) 3060, 3033, 2956, 2935, 2856, 1655, 1454, 1207, 1098, 737 cm−1; HRMS C13H18NaO2 (M+Na+) Calcd: 229.1204, Found: 229.1207.




(3) Synthesis of (3S)-4-(benzyloxy)-3-methylbutan-1-ol (P22)
This reaction was performed with reference to the literature (Gibson, S. E.; Guillo, N.; Middleton, R. J.; Thuilliez, A.; Tozer, M. J.; J. Chem. Soc., Perkin Trans., 1997, 1, 447-455.).
Water (10 ml) and formic acid (1 ml) were added to ({[(2S)-4-methoxy-2-methylbut-3-en-1-yl]oxy}methyl)benzene (3.73 g, 18 mmol) and the reaction solution was stirred at room temperature for 10 minutes. The reaction solution was diluted with ethyl acetate and washed with water, a sodium hydrogen carbonate aqueous solution and brine sequentially. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure.
Sodium borohydride (0.68 g, 18 mmol) was added to a methanol (40 ml) solution of the obtained crude product while ice cooling. After the reaction solution was stirred at the same temperature for 10 minutes, acetone was added thereto. The reaction solution was diluted with ethyl acetate and washed with brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=5:1) to obtain the title compound (3.30 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.95 (d, J=7.2 Hz, 3H), 1.51-1.68 (m, 2H), 1.89-1.99 (m, 1H), 3.31 (dd, J=7.6, 9.2 Hz, 1H), 3.39 (dd, J=4.8, 9.2 Hz, 1H), 3.61-3.75 (m, 2H), 4.52 (s, 2H), 7.26-7.37 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 17.51, 31.18, 37.74, 60.88, 73.08, 75.96, 127.57, 127.58, 128.31, 137.99; IR (neat) 3389, 3086, 3058, 3030, 2951, 2929, 2872, 1454, 1363, 1205, 1095, 738, 698 cm−1; HRMS C12H18NaO2 (M+Na+) Calcd: 217.1204, Found: 217.1190; [α]D29 −4.52 (c 2.41, CHCl3)
Step 11
Synthesis of 5-{[(3S)-4-(benzyloxy)-3-methylbutyl]sulfonyl}-1-phenyl-1H-tetrazole




(1) Synthesis of 5-{[(3S)-4-(benzyloxy)-3-methylbutyl]thio}-1-phenyl-1H-tetrazole (P23)
This reaction was performed with reference to the literature (Mitsunobu, O., Synthesis, 1981, 1-28.).
To a THF (60 ml) solution of (3S)-4-(benzyloxy)-3-methylbutan-1-ol (2.76 g, 14.2 mmol), 5-mercapto-1-phenyltetrazole (3.03 g, 17 mmol), triphenylphosphine (4.47 g, 17 mmol) and diethyl azodicarboxylate 40% toluene solution (8.04 ml, 18 mmol) were added while ice cooling. The reaction solution was warmed to room temperature and was stirred for three hours. After the reaction solution was diluted with ethyl acetate, it was washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=15:1→5:1) to obtain the title compound (5.38 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.99 (d, J=6.8 Hz, 3H), 1.65-1.74 (m, 1H), 1.92-2.03 (m, 2H), 3.26-3.52 (m, 4H), 4.49 (s, 2H), 7.21-7.35 (m, 5H), 7.49-7.58 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 16.72, 31.23, 32.82, 33.13, 73.02, 75.07, 123.78, 127.48, 128.30, 129.70, 129.99, 133.67, 138.39, 154.37; IR (neat) 3067, 3036, 2956, 2925, 2858, 1598, 1499, 1386, 1092, 761, 696 cm−1; HRMS C19H23N4OS (M+H+) Calcd: 355.1593, Found: 355.1583; [α]D27 −2.62 (c 1.56, CHCl3)




(2) Synthesis of 5-{[(3S)-4-(benzyloxy)-3-methylbutyl]sulfonyl}-1-phenyl-1H-tetrazole (P24)
This reaction was performed with reference to the literature (Shultz, H. S.; Freyermuth, H. B.; Buc, S. R., J. Org. Chem., 1963, 28(4), 1140-1142.).
About 30% hydrogen peroxide solution (16.5 ml, 146 mmol) of hexaammonium heptamolybdate tetrahydrate (1.80 g, 1.46 mmol) was added to an ethanol (20 ml) solution of 5-{[(3S)-4-(benzyloxy)-3-methylbutyl]thio}-1-phenyl-1H-tetrazole (5.17 g, 14.6 mmol) at room temperature. After the reaction solution was stirred at room temperature for 24 hours, it was diluted with ethyl acetate and washed with water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=10:1) to obtain the title compound (5.68 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.98 (d, J=6.8 Hz, 3H), 1.83-2.13 (m, 3H), 3.29 (dd, J=6.8, 9.6 Hz, 1H), 3.40 (dd, J=4.8, 9.6 Hz, 1H), 3.74-3.87 (m, 2H), 4.49 (s, 2H), 7.25-7.36 (m, 5H), 7.55-7.68 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 16.72, 26.23, 32.49, 54.30, 73.11, 74.70, 125.05, 127.55, 127.62, 128.39, 129.63, 131.37, 132.99, 138.09, 153.38; HRMS C19H23N4O3S (M+H+) Calcd: 387.1491, Found: 387.1468; [α]D26 −5.28 (c 1.00, CHCl3)
Step 12
Synthesis of (4R)-4-benzyl-3-[(2R,3S)-3-hydroxy-2-methylpentanoyl]-1,3-oxazolidin-2-one




(1) Synthesis of (4R)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one (P26)
This reaction was performed with reference to the literature (Gage, J. R.; Evans, D. A., Organic Synthesis, 1989, 68, 83-91. Chan, P. C.-M.; Chong. J. M.; Kousha, K., Tetrahedron, 1994, 150(9), 2703-2714.).
1.57M n-butyllithium hexane solution (96 ml, 150 mmol) was slowly added dropwise to a THF (400 ml) solution of (R)-4-benzyl-2-oxazolidinone (25.36 g, 143 mmol) at −78° C. under stirring. Subsequently propionyl chloride (13.7 ml, 157 mmol) was added at once and the reaction solution was stirred at the same temperature for 30 minutes. After the reaction solution was warmed to room temperature for 30 minutes, it was diluted with ethyl acetate and washed with water and brine. The organic layer was dried over anhydrous sodium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; heptane:ethyl acetate=5:1) to obtain the title compound (36.58 g) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.21 (t, J=7.2 Hz, 3H), 2.77 (dd, J=9.6, 13.2 Hz, 1H), 2.88-3.05 (m, 2H), 3.31 (dd, J=3.2, 13.2 Hz, 1H), 4.11-4.23 (m, 2H), 4.65-4.70 (m, 1H), 7.20-7.36 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 8.52, 29.42, 38.15, 55.39, 66.44, 127.56, 129.17, 129.64, 135.55, 164.52, 174.30; IR (KBr) 3082, 3026, 2984, 2942, 2872, 2360, 2338, 1787, 1702, 1496 cm−1; HRMS C13H15NNaO3 (M+Na+) Calcd: 256.0950, Found: 256.0928; [α]D27 −101.20 (c 1.11, CH3CH2OH), [α]D25 −63.9 (c 1.00, CHCl3)




(2) Synthesis of (4R)-4-benzyl-3-[(2R,35)-3-hydroxy-2-methylpentanoyl]-1,3-oxazolidin-2-one (P27)
This reaction was performed with reference to the literature (Gage, J. R.; Evans, D. A., Organic Synthesis, 1989, 68, 83-91. Chan, P. C.-M.; Chong. J. M.; Kousha, K., Tetrahedron, 1994, 50(9), 2703-2714. Cane, D. E.; Tan, W.; Ott, W. R., J. Am. Chem. Soc., 1993, 115(2) 527-535.).
To a dichloromethane (120 ml) solution of (4R)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one (17.22 g, 73.8 mmol), 1M dibutylboron triflate dichloromethane solution (150 ml, 150 mmol) and triethylamine (24.4 ml, 179 mmol) were added dropwise while ice cooling. Subsequently the reaction solution was cooled to −78° C. and propioaldehyde (10.5 ml, 145 mmol) was added dropwise over five minutes. After the reaction solution was stirred at the same temperature for one hour, it was stirred at 0° C. for two hours. The reaction solution was ice cooled again, followed by addition of a mixed solution of phosphate buffer (pH=7)-distilled water (1:3, 160 ml). After further cooled to −10° C., a mixed solution of methanol −30% hydrogen peroxide solution (2:1, 120 ml) was added thereto, and the mixture was stirred for one hour. After the reaction solution was concentrated under reduced pressure, it was diluted with diethyl ether and washed with a saturated sodium hydrogen carbonate aqueous solution and brine. The organic layer was dried over anhydrous sodium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=5:1) to obtain the title compound (16.4 g) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.98 (t, J=7.3 Hz, 3H), 1.25 (d, J=6.9 Hz, 3H), 1.40-1.64 (m, 2H), 2.77 (dd, J=9.5, 13.4 Hz, 1H), 2.88 (brs, 1H), 3.25 (dd, 3.1, 13.4 Hz, 1H), 3.80 (dq, J=2.7, 6.8 Hz, 1H), 3.85-3.89 (m, 1H), 4.17-4.25 (m, 2H), 4.68-4.74 (m, 1H), 7.19-7.36 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 10.24, 10.41, 26.72, 37.75, 41.64, 55.07, 66.13, 72.93, 127.39, 128.93, 129.38, 134.99, 152.98, 177.53; IR (KBr) 3654, 3526, 3375, 3086, 3030, 2976, 2937, 2341, 1760, 1700, 1455, 1376, 1265, 1220, 1117, 1071, 971, 930, 851, 767 cm−1; HRMS C16H21NNaO4 (M+Na+) Calcd: 314.1368, Found: 314.1381; [α]D28 −52.2 (c 1.00, CHCl3)
Step 13
Synthesis of (2R,35)-2-methyl-3-[(trietylsilyl)oxy]pentanal




(1) Synthesis of (2R,3S)—N-methoxy-N,2-dimethyl-3-[(triethylsilyl)oxy]pentanamide (P28)
This reaction was performed with reference to the literature (Nahm, S.; Weinreb, S. M., Tetrahedron Lett., 1981, 22(39), 3815-3818. Cane, D. E.; Tan, W.; Ott, W. R., J. Am. Chem. Soc., 1993, 115(2) 527-535. DiBattista, J. P.; Webster, F. X., Bioorg. Med. Chem., 1996, 4(3), 423-428.).
2M trimethylaluminum toluene solution (90 ml, 180 mmol) was added to a THF (180 ml) solution of N,O-dimethylhydroxyamine hydrochloride (18.3 g, 187.6 mmol) at −10° C. under stirring. After the reaction solution was warmed to 0° C. and stirred for 10 minutes, it was warmed to room temperature and further stirred for 30 minutes. The reaction solution was cooled to −10° C. again, and a THF-dichloromethane solution (4:5, 180 ml) of (4R)-4-benzyl-3-[(2R,3S)-3-hydroxy-2-methylpentanoyl]-1,3-oxazolidin-2-one (21.85 g, 75 mmol) was added dropwise to the reaction solution. After the reaction solution was warmed to 0° C. and stirred for two hours, a mixed solution of dichloromethane −0.5N hydrochloric acid (1:1, 80 ml) was added slowly, and the mixture was stirred for one hour at 0° C. The reaction solution was filtered through celite and the filtrate was dried over anhydrous sodium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60; heptane:ethyl acetate=1.5:1) to obtain (2R,3S)-3-hydroxy-N-methoxy-N,2-dimethylpentanamide (13.0 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.96 (t, J=7.2 Hz, 3H), 1.16 (d, J=7.2 Hz, 3H), 1.34-1.45 (m, 1H), 1.53-2.04 (m, 1H), 2.84-2.94 (m, 1H), 3.19 (s, 3H), 3.71 (s, 3H), 3.74-3.80 (m, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 10.08, 10.21, 26.64, 31.73, 38.09, 61.35, 72.95, 177.21; IR (neat) 3433, 2971, 2943, 2881, 2361, 2337, 1638, 1461, 993 cm−1; HRMS C8H17NNaO3 (M+Na+) Calcd: 198.1106, Found: 198.1100; [α]D25 −17.3 (c 1.11, CHCl3)
The above (2R,3S)-3-hydroxy-N-methoxy-N,2-dimethylpentanamide (7.3 g, 41.7 mmol) was dissolved in dichloromethane (150 ml), followed by addition of 2,6-lutidine (10.2 ml, 87 mmol) and trifluoromethanesulfonic acid triethylsilyl ester (14.1 ml, 62 mmol) while ice cooling, and the reaction solution was stirred for five hours. The reaction solution was diluted with dichloromethane and washed with a saturated ammonium chloride aqueous solution and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=10:1) to obtain the title compound (11.95 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.62 (q, J=8.0 Hz, 6H), 0.90 (t, J=7.2 Hz, 3H), 0.98 (t, J=8.0 Hz, 9H), 1.17 (d, J=6.8 Hz, 3H), 1.40-1.59 (m, 2H), 2.90-3.08 (m, 1H), 3.18 (s, 3H), 3.69 (s, 3H), 3.90 (dt, J=4.8, 8.4 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 4.96, 6.74, 8.60, 14.35, 28.25, 31.86, 40.21, 61.16, 74.50, 176.51; IR (neat) 3483, 2958, 2918, 2879, 1743, 1663, 1460, 1384, 1118, 1049, 1007, 857, 741 cm−1; HRMS C14H32NO3Si (M+H+) Calcd: 290.2151, Found: 290.2150; [α]D27 −7.39 (c 1.04, CHCl3)




(2) Synthesis of (2R,3S)-2-methyl-3-[(triethylsilyl)oxy]pentanal (P29)
This reaction was performed with reference to the literature (Nahm, S.; Weinreb, S. M., Tetrahedron Lett., 1981, 22(39), 3815-3818).
To a THF (20 ml) solution of (2R,3S)—N-methoxy-N,2-dimethyl-3-[(triethylsilyl)oxy]pentanamide (1.06 g, 3.66 mmol), 1M diisobutylaluminum hydride toluene solution (18 ml) was added dropwise at −78° C. and it was stirred at the same temperature for one hour. After 5% hydrogen chloride methanol solution (2 ml) was added to the reaction solution, the mixture was warmed to room temperature and stirred for one hour. The reaction solution was filtered through celite and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=40:1) to obtain the title compound (0.75 g) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.60 (q, J=8.0 Hz, 6H), 0.89 (t, J=7.2 Hz, 3H), 0.94 (t, J=8.0 Hz, 9H), 1.06 (d, J=6.8 Hz, 3H), 1.43-1.62 (m, 2H), 2.40-2.49 (m, 1H), 4.05 (ddd, J=3.4, 6.4, 9.6 Hz, 1H), 9.77 (s, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 5.01, 6.74, 7.43, 10.01, 27.47, 50.82, 73.33, 205.26; IR (neat) 3455, 2958, 2914, 2872, 2715, 2356, 2341, 1726, 1460, 1239, 1011, 740 cm−1; HRMS C12H26NaO2Si (M+Na+) Calcd: 253.1600, Found: 253.1596; [α]D24 −55.3 (c 1.19, CHCl3)
Step 14
Synthesis of (2S,4E,6S,7S)-2,6-dimethyl-7-[(triethylsilyl)oxy]non-4-en-1-ol




(1) Synthesis of {[(1S,2S,3E,6S)-7-(benzyloxy)-1-ethyl-2,6-dimethylhept-3-en-1-yl]oxy}(triethyl)silane (P30)
This reaction was performed with reference to the literature (Blakemore, P. R.; Cole, W. J.; Kociensky, P. J.; Morley, A., Synlett, 1998, 26-28.).
THF distilled by using lithium aluminum hydride immediately before use was used at this step.
15% toluene solution (0.65 ml) of potassium bis(trimethylsilyl)amide was added dropwise to THF (2 ml) solution of 5{[(3S)-4-(benzyloxy)-3-methylbutyl]sulfonyl}-1-phenyl-1H-tetrazole (100 mg, 0.244 mmol) at −78° C. and it was stirred at the same temperature for one hour. Subsequently a THF (0.5 ml) solution of (2R,3S)-2-methyl-3-[(triethylsilyl)oxy]pentanal (112 mg, 0.49 mmol) was added dropwise to the reaction solution at −78° C. and it was stirred for one hour. After the reaction solution was warmed to room temperature, an appropriate amount of water was added. The reaction solution was diluted with ethyl acetate and washed with brine. After the organic layer after was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:diethyl ether=100:1) to obtain the title compound (66 mg) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.60 (q, J=8.0 Hz, 6H), 0.86 (t, J=7.2 Hz, 3H), 0.91 (d, J=6.4 Hz, 3H), 0.94 (d, J=6.8 Hz, 3H), 0.96 (t, J=8.0 Hz, 9H), 1.34-1.49 (m, 2H), 1.78-1.93 (m, 2H), 2.11-2.19 (m, 1H), 2.20-2.27 (m, 1H), 3.24 (dd, J=6.0, 8.8 Hz, 1H), 3.33 (dd, J=6.0, 8.8 Hz, 1H), 3.42 (dt, J=5.2, 5.6 Hz, 1H), 4.49 (s, 2H), 5.31-5.41 (m, 2H), 7.26-7.36 (m, 5H); IR (neat) 3086, 3067, 3033, 2958, 2903, 2879, 1500, 1456, 1102, 1011, 737 cm−1; HRMS C24H42AgO2Si (M+Ag+) Calcd: 497.2005, Found: 497.1981
100 MHz 13C-NMR (CDCl3) δ (ppm) 5.18, 6.97, 9.35, 16.15, 16.84, 26.81, 33.80, 36.83, 41.73, 72.92, 75.33, 77.44, 127.34, 127.44, 127.48, 128.23, 134.81, 138.77; [α]D25 −16.07 (c 1.28, CHCl3).




(2) Synthesis of (2S,4E,6S,7S)-2,6-dimethyl-7-[(triethylsilyl)oxy]non-4-en-1-ol (P31)
This reaction was performed with reference to the literature (Shimshock, S. J.; Waltermire, R. E.; DeShong, P., J. Am. Chem. Soc., 1991, 113, 8791-8796.).
Lithium (39.4 mg, 5.62 mmol) was added to a THF (25 ml) solution of di-tert-butyldiphenyl (1.87 g, 7.02 mmol) while ice cooling and the reaction solution was stirred at room temperature for three hours. The reaction solution turned dark green during stirring. This solution was added dropwise to THF (5 ml) solution of {[(1S,2S,3E,6S)-7-benzyloxy-1-ethyl-2,6-dimethylhept-3-en-1-yl]oxy}(triethyl)silane (500 mg, 1.28 mmol) slowly (at such a rate that green of the reaction solution was maintained) cooled to −78° C. under stirring. After the reaction solution was stirred at the same temperature for three hours, a saturated ammonium chloride aqueous solution was added thereto and the mixture was warmed to room temperature. After the reaction solution was diluted with ethyl acetate, it was washed with brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=15:1) to obtain the title compound (296 mg) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.60 (q, J=8.0 Hz, 6H), 0.87 (t, J=7.6 Hz, 3H), 0.90 (d, J=6.8 Hz, 3H), 0.95 (d, J=7.6 Hz, 3H), 0.96 (t, J=8.0 Hz, 9H), 1.34-1.50 (m, 2H), 1.65-1.76 (m, 1H), 1.87-1.94 (m, 1H), 2.09 (ddd, 5.6, 5.6, 14.0 Hz, 1H), 2.21-2.29 (m, 1H), 3.42-3.48 (m, 2H), 3.51 (dd, J=6.0, 10.4 Hz, 1H), 5.30-5.46 (m, 2H); IR (neat) 3342, 2958, 2916, 2877, 1459, 1415, 1380, 1013, 741 cm−1; HRMS C17H36AgO2Si (M+Ag+) Calcd: 407.1536, Found: 407.1512
100 MHz 13C-NMR (CDCl3) δ (ppm) 5.11, 6.90, 9.39, 16.05, 16.37, 26.67, 35.96, 36.69, 41.71, 67.81, 77.46, 127.57, 134.84; [α]D25 −24.74 (c 1.36, CHCl3).
Step 15
Synthesis of (3S,4S,5E,8S)-4,8-dimethyl-9-[(1-phenyl-1H-tetrazol-5-yl)sulfonyl]non-5-en-3-ol




(1) Synthesis of 5-{(2S,4E,6S,7S)-2,6-dimethyl-7-[(triethylsilyl)oxy]non-4-en-1-yl}thio)-1-phenyl-1H-tetrazole (P32)
This reaction was performed with reference to the literature (Mitsunobu, O., Synthesis, 1981, 1-28.).
After 5-mercapto-1-phenyltetrazole (237 mg, 1.33 mmol) and triphenylphosphine (350 mg, 1.33 mmol) were added to a THF (10 ml) solution of (2S,4E,6S,7S)-2,6-dimethyl-7-[(triethylsilyl)oxy]non-4-en-1-ol (334 mg, 1.11 mmol) at room temperature, 40% toluene solution of diethyl azodicarboxylate (0.63 ml, 1.44 mmol) was added dropwise to while ice cooling. After the reaction solution was stirred at room temperature for three hours, it was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=40:1) to obtain the title compound (457 mg) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.59 (q, J=8.0 Hz, 6H), 0.85 (t, J=7.6 Hz, 3H), 0.95 (d, J=6.8 Hz, 3H), 0.95 (t, J=8.0 Hz, 9H), 1.03 (d, J=6.0 Hz, 3H), 1.32-1.52 (m, 2H), 1.97-2.06 (m, 2H), 2.18-2.29 (m, 2H), 3.28 (dd, J=6.4, 12.8 Hz, 1H), 3.41-3.45 (m, 2H), 5.32-5.39 (m, 1H), 5.45 (dd, J=7.2, 15.2 Hz, 1H), 7.52-7.60 (m, 5H); IR (neat) 2958, 2883, 1594, 1500, 1459, 1383, 1240, 1013, 742 cm−1; HRMS C24H41N4OSSi (M+H+) Calcd: 461.2770, Found: 461.2787
100 MHz 13C-NMR (CDCl3) δ (ppm) 5.09, 6.90, 9.40, 16.05, 15.86, 18.80, 26.64, 33.09, 38.84, 39.71, 41.68, 77.29, 123.75, 126.09, 129.66, 129.95, 133.68, 135.96, 154.56; [α]D25 −22.0 (c 1.51, CHCl3).




(2) Synthesis of (3S,4S,5E,8S)-4,8-dimethyl-9-[(1-phenyl-1H-tetrazol-5-yl)sulfonyl]non-5-en-3-ol (P33)
This reaction was performed with reference to the literature (Shultz, H. S.; Freyermuth, H. B.; Buc, S. R., J. Org. Chem., 1963, 28(4), 1140-1142.).
About 30% hydrogen peroxide solution (1.29 ml, 11.4 mmol) solution of hexaammonium heptamolybdate tetrahydrate (140 mg, 0.12 mmol) was added to an ethanol (10 ml) solution of 5-{(2S,4E,6S,7S)-2,6-dimethyl-7-[(triethylsilyl)oxy]non-4-en-1-yl}thio)-1-phenyl-1H-tetrazole (444 mg, 1.14 mmol) at room temperature and the reaction solution was stirred for 24 hours. The reaction solution was diluted with ethyl acetate and washed with water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=5:1-1:1) to obtain the title compound (300 mg) as a colorless oil. (The title compound crystallized from hexane-ethyl acetate.)
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.95 (t, J=7.3 Hz, 3H), 1.01 (d, J=6.8 Hz, 3H), 1.16 (d, J=6.6 Hz, 3H), 1.31-1.42 (m, 1H), 1.42-1.49 (m, 1H), 1.49-1.59 (m, 1H), 2.20 (dd, J=6.2, 6.4 Hz, 2H), 2.23-2.31 (m, 1H), 2.37-2.47 (m, 1H), 3.34-3.42 (m, 1H), 3.53 (dd, J=7.4, 14.5 Hz, 1H), 3.88 (dd, J=4.8, 14.5 Hz, 1H), 5.39-5.47 (m, 1H), 5.50 (dd, J=7.2, 15.6 Hz, 1H), 7.57-7.70 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 10.24, 14.79, 19.60, 26.92, 28.25, 39.35, 42.14, 60.73, 76.35, 125.02, 126.09, 129.55, 131.34, 132.92, 137.02, 153.88; IR (KBr) 3384, 3351, 3316, 2961, 2939, 2879, 2356, 2338, 1593, 1499, 1459, 1332, 1156, 1098, 1019, 967, 840, 768, 691, 633 cm−1; HRMS C18H27N4O3S (M+H+) Calcd: 379.1804, Found: 379.1806; [α]D23 −29.5 (c 1.20, CHCl3)
Step 16
Synthesis of 5-({(2S)-3-[(2R,3R)-3-((1S,2S)-2-{[diethyl(isopropyl)silyl]oxy}-1-methylbutyl)oxiran-2-yl]-2-methylpropyl}sulfonyl)-1-phenyl-1H-tetrazole)




(1) Synthesis of (2R,3S)-2-((2R,3R)-3-{(2S)-2-methyl-3-[(1-phenyl-1H-tetrazol-5-yl)sulfonyl]propyl}oxiran-2-yl)pentane-3-ol (P34)
This reaction was performed with reference to the literature (Wang, Z., -X.; Tu, Y.; Frohn, M.; Zhang, J.-R.; Shi, Y., J. Am. Chem. Soc., 1997, 119, 11224-11235. Wang, Z., -X.; Tu, Y.; Frohn, M.; Zhang, J.-R.; Shi, Y., J. Org. Chem., 1997, 62, 2328-2329.).
(3S,4S,5E,8S)-4,8-dimethyl-9-[(1-phenyl-1H-tetrazol-5-yl)sulfonyl]non-5-en-3-ol (190 mg, 0.50 mmol) was dissolved in acetonitrile (7.5 ml) and 0.05M sodium tetraborate decahydrate −0.4 mM disodium ethylenediaminetetraacetate salt solution (5 ml). 1,2:4,5-di-O-isopropylidene-D-erythro-2,3-hexodiuro-2,6-pyranose (450 mg, 1.74 mmol) was added while ice cooling. Subsequently, a mixed powder of potassium carbonate (0.85 mg, 6.16 mmol) and oxone (1.27 g, 2.06 mmol) was added at the same temperature over one hour. The reaction solution was stirred at the same temperature for further one hour. The reaction solution was diluted with ethyl acetate and washed with water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=3:1) to obtain the title compound (160 mg, 94% ee) as a colorless oil. The optical purity was determined by HPLC using a chiral column (DAICEL, commercial name CHIRALCEL OD; n-hexane:isopropylalcohol=75:25).
This oil was crystallized from hexane at −78° C. and recrystallized further from a mixed solvent of hexane-ethyl acetate and the title compound (140 mg, >99% ee) was obtained as a colorless prism. In addition, (2S)-2-((2R,3R)-3-{(2S)-2-methyl-3-[(1-phenyl-1H-tetrazol-5-yl)sulfonyl]propyl}oxiran-2-yl)pentan-3-one (P34b, 34 mg) was obtained as colorless oil, as a by-product of this procedure.
Compound P34: 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.98 (d, J=7.1 Hz, 3H), 0.99 (t, J=7.3 Hz, 3H), 1.26 (d, J=6.8 Hz, 3H), 1.29-1.37 (m, 1H), 1.45-1.63 (m, 3H), 1.89 (ddd, J=4.6, 5.8, 14.3 Hz, 1H), 2.45-2.57 (m, 1H), 2.69 (dd, J=2.2, 7.9 Hz, 1H), 2.86 (ddd, J=2.2, 4.6, 6.9 Hz, 1H), 3.57 (dt, J=4.6, 8.8 Hz, 1H), 3.69 (dd, J=7.3, 14.8 Hz, 1H), 3.91 (dd, J=5.2, 14.8 Hz, 1H), 7.66-7.77 (m, 5H); 100 MHZ 13C-NMR (CD3OD) δ (ppm) 10.54, 10.87, 20.29, 28.32, 28.57, 39.26, 42.23, 56.63, 61.67, 62.23, 75.15, 126.94, 130.58, 132.54, 134.54, 155.41; IR (KBr) 3336, 3245, 2961, 2925, 2900, 2869, 1779, 1594, 1460, 1334, 1154, 1109, 1071, 981, 955, 828, 765, 688, 634, 524, 456 cm−1; HRMS C18H27N4O4S (M+H+) Calcd: 395.1753, Found: 395.1721; [α]D20 −21.0 (c 1.00, CH3OH)
Compound P34b: 400 MHz 1H-NMR (CDCL3) δ (ppm) 1.03 (t, J=7.3 Hz, 3H), 1.12 (d, J=7.1 Hz, 3H), 1.28 (d, J=6.9 Hz, 3H), 1.56 (ddd, J=7.4, 7.4, 14.8 Hz, 1H), 1.96 (ddd, J=4.6, 5.8, 14.8 Hz, 1H), 2.31-2.45 (m, 1H), 2.45-2.65 (m, 3H), 2.75-2.83 (m, 2H), 3.65 (dd, J=7.1, 14.6 Hz, 1H), 3.93 (dd, J=5.3, 14.6 Hz, 1H), 7.56-7.71 (m, 5H); 100 MHZ 13C-NMR (CD3OD) δ (ppm) 7.74-12.93, 20.33, 28.30, 36.12, 39.00, 49.48, 56.62, 60.05, 62.22, 127.03, 130.62, 132.60, 134.63, 155.47, 214.55; HRMS; C18H25N4O4S+ Calcd: 393.1597, Found: 393.1601 (M+H)+; [α]D24 +52.25 (c 0.86, CH3OH).




(2) Synthesis of 5-({(2S)-3-[(2R,3R)-3-(1S,2S)-2-{[diethyl(isopropyl)silyl]oxy-1-methylbutyl)oxiran-2-yl}-2-methylpropyl}sulfonyl)-1-phenyl-1H-tetrazole (P35)
Imidazole (345 mg, 5.07 mmol) and diethylisopropylsilyl chloride (418 mg, 2.54 mmol) were added to a DMF (4 ml) solution of (2R,3S)-2-((2R,3R)-3-{(2S)-2-methyl-3-[(1-phenyl-1H-tetrazol-5-yl)sulfonyl]propyl}oxiran-2-yl)pentane-3-ol (200 mg, 0.507 mmol) at room temperature, and the mixture was stirred at the same temperature for one hour. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=20:1→10:1) to obtain the title compound (265 mg) as a colorless oil.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.67-0.74 (m, 4H), 0.88 (t, 3H), 0.95 (d, J=6.8 Hz, 3H), 0.90-0.98 (m, 1H), 1.04 (t, J=7.6 Hz, 3H), 1.05 (t, J=7.6 Hz, 3H), 1.06 (d, J=5.6 Hz, 6H), 1.26 (d, J=6.8 Hz, 3H), 1.32-1.43 (m, 1H), 1.52-1.63 (m, 3H), 1.92 (ddd, J=4.4, 6.0, 14.0 Hz, 1H), 2.45-2.56 (m, 1H), 2.71 (dd, J=2.4, 7.6 Hz, 1H), 2.86 (ddd, J=2.4, 4.4, 6.8 Hz, 1H), 3.70 (dd, J=7.6, 14.8 Hz, 1H), 3.80-3.86 (m, 1H), 3.90 (dd, J=5.2, 14.8 Hz, 1H), 7.65-7.75 (m, 5H); 100 MHz 13C-NMR (CD3OD) δ (ppm) 5.00, 5.17, 7.65, 10.02, 10.11, 14.40, 17.93, 20.31, 28.46, 28.64, 39.40, 40.84, 57.28, 61.58, 62.28, 75.78, 126.99, 130.63, 132.58, 134.71, 155.54; IR (neat) 2961, 2881, 1596, 1498, 1462, 1339, 1153, 1014, 823, 763, 723, 633 cm−1; HRMS C25H43N4O4SSi (M+H+) Calcd: 523.2774, Found: 523.2766; [α]D23 +19.3 (c 1.09, CH3OH)
Step 17
Synthesis of 6,7-O—[(S)-benzylidene]pladienolide A




(1) Synthesis of 6,7-O—[(S)-benzylidene]-3-{[tert-butyl(dimethyl)silyl]oxy}-21-{[diethyl(isopropyl)silyl]oxy}-pladienolide A (36)
This reaction was performed with reference to the literature (Blakemore, P. R.; Cole, W. J.; Kociensky, P. J.; Morley, A., Synlett, 1998, 26-28.).
THF distilled by using lithium aluminum hydride immediately before use was used at this step.
15% toluene solution (0.317 ml) of potassium bis(trimethylsilyl)amide was added dropwise to a THF (1 ml) solution of 5-({(2S)-3-[(2R,3R)-3-(1S,2S)-2-{[diethyl(isopropyl)silyl]oxy-1-methylbutyl)oxiran-2-yl}-2-methylpropyl}sulfonyl)-1-phenyl-1H-tetrazole (62 mg, 0.119 mmol) at −78° C. under stirring and it was stirred at the same temperature for 30 minutes. A THF (1 ml) solution of (2E)-3-((2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-6,13a-dimethyl-9-oxo-2-phenyl-6,7,9,10,11,12,13,13a-octahydro-3aH-[1,3]dioxolo[4,5-f]oxacyclododecin-7-yl)but-2-enal (94 mg, 0.179 mmol) was added dropwise to this reaction solution at −78° C. and stirred at the same temperature for one hour. The reaction solution was warmed to room temperature and diluted with ethyl acetate after addition of an appropriate amount of water and washed with brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=25:1-15:1) to obtain the title compound (65 mg) as a colorless oil.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.15 (s, 3H), 0.17 (s, 3H), 0.66-0.75 (m, 4H), 0.86 (t, J=7.6 Hz, 3H), 0.90 (d, J=6.8 Hz, 3H), 0.93 (d, J=6.8 Hz, 3H), 0.95 (s, 9H), 0.94-1.03 (m, 1H), 1.05 (t, J=8.4 Hz, 6H), 1.07 (d, J=6.4 Hz, 6H), 1.12 (d, J=6.8 Hz, 3H), 1.24-1.35 (m, 1H), 1.38-1.50 (m, 3H), 1.42 (s, 3H), 1.58 (dq, J=7.6, 14.4 Hz, 2H), 1.69-1.78 (m, 2H), 1.78 (s, 3H), 1.96-2.05 (m, 1H), 2.28 (dd, J=10.2, 14.8 Hz, 1H), 2.44-2.58 (m, 1H), 2.64-2.72 (m, 3H), 2.76 (dt, J=2.4, 6.0 Hz, 1H), 3.80-3.86 (m, 1H), 4.05-4.13 (m, 1H), 4.28 (d, J=9.6 Hz, 1H), 4.96 (d, J=10.8 Hz, 1H), 5.50 (dd, J=9.6, 15.2 Hz, 1H), 5.68 (dd, J=9.6, 14.4 Hz, 1H), 5.70 (dd, J=9.6, 15.2 Hz, 1H), 5.94 (s, 1H), 6.12 (d, 10.8 Hz, 1H), 6.36 (dd, J=10.8, 14.4 Hz, 1H), 7.40-7.44 (m, 3H), 7.52-7.54 (m, 2H); 100 MHz 13C-NMR (CD3COCD3) δ (ppm) −4.94, −4.85, 4.06, 4.24, 7.02, 7.05, 9.44, 9.76, 11.17, 13.33, 16.70, 17.32, 17.92, 21.07, 22.61, 25.64, 27.74, 31.69, 34.80, 35.51, 40.00, 40.08, 40.19, 44.08, 56.95, 60.92, 71.89, 74.66, 82.34, 83.54, 85.35, 101.21, 124.75, 127.09, 128.24, 129.11, 130.29, 130.76, 131.79, 137.63, 139.00, 141.19, 168.35; IR (neat)=2959, 1732, 1462, 1376, 1276, 1247, 1064, 1008, 971, 881, 836, 775, 760, 722, 564, 536, 463 cm−1; HRMS C48H80NaO7Si2 (M+Na+) Calcd: 847.5340, Found: 847.5323.; [α]D26 +21.3 (c 1.09, CH2Cl2)




(2) Synthesis of 6,7-O—[(S)-benzylidene]pladienolide A (P37)
1M THF solution (3.80 ml, 696 μmol) of tetra-n-butylammonium fluoride (3.80 ml, 696 μmol) was added to a THF (3.80 ml) solution of 6,7-O—[(S)-benzylidene]-3-{[tert-butyl(dimethyl)silyl]oxy}-21-{[diethyl(isopropyl)silyl]oxy}-pladienolide A (191 mg, 232 μmol) at room temperature. The reaction solution was stirred at room temperature for one and a half hour. The reaction solution was poured into a saturated ammonium chloride aqueous solution, which was then extracted with ethyl acetate. The organic layer was washed with water and brine sequentially and dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=2:1→1:1) to obtain the title compound (135 mg) as a colorless oil.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.93 (d, J=7.2 Hz, 3H), 0.94 (d, J=7.2 Hz, 3H), 0.98 (t, J=7.4 Hz, 3H), 1.13 (d, J=6.8 Hz, 3H), 1.18-1.29 (m, 1H), 1.44 (s, 3H), 1.44-1.60 (m, 6H), 1.64-1.72 (m, 1H), 1.79 (d, J=1.2 Hz, 3H), 2.00-2.10 (m, 1H), 2.33 (dd, J=9.8, 14.6 Hz, 1H), 2.46-2.56 (m, 1H), 2.62-2.78 (m, 3H), 3.55 (dt, J=4.8, 8.0 Hz, 1H), 3.93-4.01 (m, 1H), 4.28 (d, J=9.2 Hz, 1H), 4.97 (d, J=10.4 Hz, 1H), 5.49 (dd, J=9.6, 14.8 Hz, 1H), 5.69 (dd, J=9.2, 14.8 Hz, 2H), 5.94 (s, 1H), 6.13 (brd, J=11.0 Hz, 1H), 6.36 (dd, J=11.0, 14.8 Hz, 1H), 7.40-7.43 (m, 3H), 7.51-7.34 (m, 2H); 100 MHz 13C-NMR (CD3COCD3) δ (ppm) 10.20, 10.30, 11.26, 16.48, 20.87, 22.33, 27.88, 31.04, 34.09, 35.51, 39.80, 40.20, 41.53, 42.71, 56.45, 61.31, 70.01, 73.62, 82.39, 83.66, 85.21, 101.20, 124.65, 127.09, 128.30, 129.14, 130.49, 130.86, 131.74, 137.37, 139.11, 141.32, 169.85; IR (neat) 3502, 2965, 2931, 2874, 1711, 1456, 1377, 1246, 1221, 1178, 1092, 1064, 971, 761 cm−1; HRMS C35H50NaO7 (M+Na+) Calcd: 605.3454, Found: 605.3449; [α]D24 −13.0 (c 1.05, CH2Cl2)
Step 18
Synthesis of Pladienolide A




(1) Synthesis of 6,7-O—[(S)-benzylidene]-3,21-bis(dichloroacetyl) pladienolide A (P38)
Triethylamine (686 μl, 4.92 mmol), dichloroacetic anhydride (375 μl, 2.46 mmol) and 4-dimethylaminopyridine (15 mg, 123 μmol) were added to anhydrous dichloromethane (7.20 ml) solution of 6,7-O-[(S)-benzylidene]pladienolide A (144 mg, 2.46 mmol) under stirring at 0° C. After the reaction solution was stirred at 0° C. for 40 minutes, 4-dimethylaminopyridine (15 mg, 123 μmol) was added thereto and the mixture was stirred at 0° C. for further one and a half hour. The reaction solution was poured into water, which was then extracted with ethyl acetate. The organic layer was washed with water and brine sequentially and dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; n-heptane:ethyl acetate=8:1→6:1→4:1) to obtain the title compound (198 mg) as a yellow oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.88 (d, J=6.8 Hz, 3H), 0.93 (t, J=7.6 Hz, 3H), 0.95 (d, J=6.8 Hz, 3H), 1.07 (d, J=6.8 Hz, 3H), 1.41 (s, 3H), 1.46-1.60 (m, 3H), 1.62-1.68 (m, 1H), 1.68-1.81 (m, 4H), 1.73 (s, 3H), 1.94-2.05 (m, 1H), 2.40-2.56 (m, 3H), 2.56-2.78 (m, 2H), 2.83 (dd, J=4.2, 15.0 Hz, 1H), 4.21 (d, J=9.2 Hz, 1H), 4.92 (d, J=10.4 Hz, 1H), 5.02-5.08 (m, 1H), 5.12-5.22 (m, 1H), 5.42 (dd, J=9.6, 15.2 Hz, 1H), 5.62 (dd, J=8.4, 14.8 Hz, 1H), 5.67 (dd, J=9.6, 15.2 Hz, 1H), 5.92 (s, 1H), 5.93 (s, 1H), 5.96 (s, 1H), 6.09 (d, J=10.8 Hz, 1H), 6.24 (dd, J=10.8, 14.8 Hz, 1H), 7.37-7.42 (m, 3H), 7.49-7.52 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 9.62, 10.96, 11.73, 16.48, 21.04, 22.62, 24.79, 27.87, 32.99, 35.31, 38.87, 39.30, 39.55, 40.13, 56.41, 60.03, 64.14, 64.58, 75.78, 80.54, 83.02, 83.19, 85.06, 101.26, 124.45, 126.61, 128.33, 129.31, 129.64, 130.86, 131.04, 137.44, 137.74, 141.03, 164.06, 167.56; IR (neat) 3015, 2972, 2931, 2877, 1759, 1739, 1576, 1457, 1377, 1281, 1248, 1171, 1092, 1066, 1004, 968, 911, 816, 758, 699 cm−1; HRMS C39H50Cl4O9Na (M+Na+) Calcd: 825.2107, Found: 825.2120; [α]D23+15.0 (c 1.02, CH2Cl2)




(2) Synthesis of 3,21-bis(dichloroacetyl) pladienolide A (24)
Pyridinium p-toluenesulfonate (70.5 mg, 280 μmol) was added to a methanol (4.48 ml) solution of 6,7-O—[(S)-benzylidene]-3,21-bis(dichloroacetyl pladienolide A (112 mg, 140 μmol) at room temperature. The reaction solution was stirred at room temperature for 46 hours. The reaction solution was poured into brine, which was then extracted with ethyl acetate. The organic layer was washed with water and brine sequentially and dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; n-heptane:ethyl acetate=8:1→6:1→3:1→3:2→1:1) to obtained title compound (32.2 mg) as a colorless oil while 6,7-O—[(S)-benzylidene]-3,21-bis(dichloroacetyl) pladienolide A (55.9 mg) was recovered.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.90 (d, J=7.2 Hz, 3H), 0.93 (t, J=7.2 Hz, 3H), 0.96 (d, J=7.2 Hz, 3H), 1.06 (d, J=6.8 Hz, 3H), 1.32 (s, 3H), 1.43-1.62 (m, 5H), 1.63-1.69 (m, 2H), 1.72 (s, 3H), 1.72-1.79 (m, 2H), 2.00 (brs, 1H), 2.41-2.48 (m, 1H), 2.51-2.58 (m, 3H), 2.61 (dd, J=3.2, 15.2 Hz, 1H), 2.66-2.70 (m, 1H), 2.74 (dd, J=4.0, 15.2 Hz, 1H), 3.80 (dd, J=2.6, 9.8 Hz, 1H), 4.93-4.97 (m, 1H), 5.01-5.05 (m, 1H), 5.05 (d, J=10.4 Hz, 1H), 5.47 (dd, J=9.8, 15.3 Hz, 1H), 5.61 (dd, J=8.0, 15.1 Hz, 1H), 5.74 (dd, J=9.6, 15.3 Hz, 1H), 5.97 (s, 1H), 5.98 (s, 1H), 6.07 (brd, J=10.4 Hz, 1H), 6.24 (dd, J=10.4, 15.1 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 9.68, 11.00, 11.77, 16.51, 21.08, 24.60, 24.83, 25.61, 34.76, 35.35, 36.17, 39.34, 39.61, 40.47, 56.48, 60.07, 64.27, 64.61, 73.28, 74.59, 80.60, 83.08, 124.52, 129.71, 130.86, 131.11, 137.79, 141.06, 163.91, 164.17, 168.05; IR (neat) 3526, 2971, 2929, 1759, 1745, 1456, 1377, 1281, 1217, 1171, 1092, 1008, 964, 927, 816, 757 cm−1; HRMS C32H46Cl4NaO9 (M+Na+) Calcd: 737.1794, Found: 737.1778; [α]D27 +22.5 (c 1.52, CHCl3)




(3) Synthesis of pladienolide A
Potassium carbonate (13.5 mg, 97.5 μmol) was added to a methanol (2.50 ml) solution of 3,21-bis(dichloroacetyl) pladienolide A (69.9 mg, 97.5 μmol) at room temperature. After the reaction solution was stirred at room temperature for 20 minutes, it was poured into brine, which was then extracted with ethyl acetate. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:acetone=3:2→1:1) to obtain the title compound (46.2 mg) as a colorless oil. This was obtained as a white amorphous by purifying by HPLC (Shiseido, commercial name CAPCELL PAK C18SG120; acetonitrile:water=37:63) followed by performing lyophilization.
600 MHz 1H-NMR (CD3OD) δ (ppm) 0.95 (d, J=7.0 Hz, 3H), 0.95 (d, J=6.7 Hz, 3H), 0.98 (t, J=7.4 Hz, 3H), 1.13 (d, J=6.8 Hz, 3H), 1.24 (m, 1H), 1.31 (s, 3H), 1.38 (m, 2H), 1.50 (m, 1H), 1.53 (m, 2H), 1.57 (m, 1H), 1.61 (m, 1H), 1.68 (ddd, J=5.5, 5.9, 14.0 Hz, 1H), 1.79 (brs, 3H), 2.52 (m, 1H), 2.56 (m, 2H), 2.61 (ddq, J=7.0, 9.8, 10.7 Hz, 1H), 2.70 (dd, J=2.2, 8.2 Hz, 1H), 2.77 (ddd, J=2.2, 5.9, 5.9 Hz, 1H), 3.56 (ddd, J=4.5, 4.5, 8.7 Hz, 1H), 3.74 (d, J=9.8 Hz, 1H), 3.81 (m, 1H), 5.07 (d, J=10.7 Hz, 1H), 5.42 (dd, J=9.8, 15.0 Hz, 1H), 5.70 (dd, J=8.4, 15.0 Hz, 1H), 5.76 (dd, J=9.8, 15.0 Hz, 1H), 6.13 (brd, J=10.8 Hz, 1H), 6.37 (dd, J=10.8, 15.0 Hz, 1H); 150 MHz 13C-NMR (CD3OD) δ (ppm) 10.8, 10.9, 11.9, 17.1, 21.7, 24.4, 28.6, 30.5, 36.7, 37.6, 40.1, 40.7, 1.8, 42.8, 58.5, 63.0, 70.7, 74.7, 75.3, 78.2, 84.4, 125.9, 131.6, 132.1, 132.6, 137.7, 142.3, 171.9; IR (KBr) 3403, 2966, 2935, 2876, 1708, 1458, 1371, 1256, 1177, 1060, 1021, 977, 903, 789 cm−1; HRMS C28H46NaO7 (M+Na+) Calcd: 517.3141, Found: 517.3134; [α]D27 −1.54 (c 1.02, MeOH)
Step 19
Synthesis of Pladienolide B




Triethylamine (17.2 μl, 123 μmol), acetic anhydride (5.83 μl, 616 μmol) and 4-dimethylaminopyridine (1.50 mg, 12.3 μmol) were added to anhydrous dichloromethane (2.00 ml) solution of pladienolide A (30.5 mg, 61.6 μmol) under stirring at 0° C. After the reaction solution was stirred at 0° C. for one hour, it was poured into a saturated sodium hydrogen carbonate aqueous solution, which was then extracted with ethyl acetate. After the organic layer was washed with brine, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto Chemical, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:acetone=3:1→2:1) to obtain the title compound (27.2 mg) as a colorless oil. This was obtained as a white amorphous by purifying by HPLC (Shiseido, commercial name CAPCELL PAK C18SG120; acetonitrile:water=45:55) followed by performing lyophilization.
600 MHz 1H-NMR (CD3OD) δ (ppm) 0.93 (d, J=6.8 Hz, 3H), 0.95 (d, J=7.0 Hz, 3H), 0.98 (t, J=7.4 Hz, 3H), 1.13 (d, J=6.8 Hz, 3H), 1.23 (s, 3H), 1.24 (m, 1H), 1.41 (m, 1H), 1.42 (m, 1H), 1.51 (m, 1H), 1.53 (m, 2H), 1.61 (m, 1H), 1.67 (m, 1H), 1.68 (m, 1H), 1.79 (brs, 3H), 2.10 (s, 3H), 2.52 (m, 1H), 2.57 (m, 2H), 2.61 (ddq, J=6.8, 9.9, 10.1 Hz, 1H), 2.70 (dd, J=2.2, 8.2 Hz, 1H), 2.77 (ddd, J=2.2, 5.9, 5.9 Hz, 1H), 3.55 (ddd, J=4.5, 4.5, 8.7 Hz, 1H), 3.82 (m, 1H), 5.09 (d, J=9.8 Hz, 1H), 5.09 (d, J=10.1 Hz, 1H), 5.61 (dd, J=9.9, 15.2 Hz, 1H), 5.70 (dd, J=8.4, 15.0 Hz, 1H), 5.74 (dd, J=9.8, 15.2 Hz, 1H), 6.13 (brd, J=10.8 Hz, 1H), 6.37 (dd, J=10.8, 15.0 Hz, 1H); 150 MHz 13C-NMR (CD30D) δ (ppm) 10.8, 10.9, 11.9, 16.9, 21.1, 21.7, 24.2, 28.6, 30.4, 31.1, 36.7, 37.5, 40.1, 40.7, 41.7, 42.8, 58.5, 63.0, 70.4, 74.1, 75.3, 80.3, 84.3, 125.8, 127.0, 132.2, 132.4, 141.6, 142.3, 171.8, 172.2; IR (KBr) 3447, 2966, 2935, 2875, 1735, 1720, 1458, 1372, 1244, 1175, 1022, 978, 910, 551, 478 cm−1; HRMS C30H48NaO8 (M+Na+) Calcd: 559.3247, Found: 559.3227; [α]D27 +7.90 (c 1.10, MeOH)
Synthesis of a Compound Analogous to Pladienolide B




Synthesis of 21-{[tert-butyl(dimethyl)silyl]oxy}pladienolide B (R2)
This reaction is performed with reference to the literature (Grubbs, R. H. “Hand book of Metathesis”, Wiley-VCH, 2003, v. 2, p 246-292).
(i) (2S,3S,4E,6S,7R,10R)-7,10-dihydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate (11.0 mg, 30.0 μmol) and tert-butyl[((1S,2S)-1-ethyl-2{(2R,3R)-3-[(2S)-2-methylbut-3-en-1-yl]oxiran-2-yl]propyl)oxy}dimethylsilane (24.0 mg 76.8 μmol) were dissolved in anhydrous dichloromethane under argon atmosphere and the second generation Grubbs catalyst; [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)-tricyclohexylphosphine)ruthenium was added. The reaction solution was heated to reflux for three hours. After the reaction solution was cooled to room temperature, it was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=1:1) to obtain the title compound (5.1 mg) as a colorless amorphous.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.12 (s, 6H), 0.86 (t J=7.6 Hz, 3H), 0.90 (d, J=7.2 Hz, 3H), 0.92 (d, J=7.6 Hz, 3H), 0.95 (s, 9H), 1.12 (d, J=6.8 Hz, 3H), 1.23 (s, 3H), 1.22-1.78 (m, 9H), 1.78 (s, 3H), 2.10 (s, 3H), 2.46-2.64 (m, 4H), 2.66 (dd, J=2.4, 8.8 Hz, 1H), 2.76 (dt, J=2.4, 6.0 Hz, 1H), 3.78-3.86 (m, 2H), 5.00-5.14 (m, 2H), 5.52-5.80 (m, 3H), 6.12 (brd, J=10.8 Hz, 1H), 6.36 (dd, J=10.8, 15.2 Hz, 1H); LRMS C36H62NaO8Si (M+Na+) Calcd: 673.41, Found: 673.26.
Total Synthesis of Pladienolide D
Step D1
Methyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)sulfonyl]pent-2-enoate and ethyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)thio]pent-2-enoate




(1-1) Synthesis of methyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)thio]pent-2-enoate (Q1a)
5-Mercapto-1-phenyltetrazole (2.62 g, 14.60 mmol), triphenylphosphine (3.83 g, 14.60 mmol) and diisopropyl azodicarboxylate (95%, 2.96 g, 14.60 mmol) were added to a THF (36.8 ml) solution of methyl-(2E)-5-hydroxy-3-methylpent-2-enoate (1.16 g, 7.31 mmol) while ice cooling. The reaction solution was warmed to room temperature and stirred for two hours. After the reaction solution was diluted with ethyl acetate, it was washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=5:1) to obtain the title compound (2.33 g) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 2.22 (d, J=1.2 Hz, 3H), 2.70 (t, J=7.2 Hz, 2H), 3.54 (t, J=7.2 Hz, 2H), 3.70 (s, 3H), 5.70-5.74 (q, J=1.2 Hz, 1H), 7.52-7.59 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 18.41, 30.75, 39.68, 50.94, 117.30, 123.73, 129.81, 130.18, 133.46, 153.79, 155.84, 166.49; IR (KBr)=3071, 2991, 2948, 1707, 1648, 1593, 1499, 1437, 1412, 1380, 1226, 1153, 1057, 877, 761, 693, 559, 485, 407 cm−1; HRMS C14H16AgN4O2S (M+Ag+) Calcd: 411.0045, Found: 411.0073.




(1-2) Synthesis of ethyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)thio]pent-2-enoate (Q1b)
This reaction was performed with reference to the literature (Mitsunobu, O., Synthesis, 1981, 1-28.). 5-Mercapto-1-phenyltetrazole (16.30 g, 91.20 mmol), triphenylphosphine (27.30 g, 104 mmol) and diisopropyl azodicarboxylate (95%, 21.10 g, 104 mmol) were added to a THF (410 ml) solution of ethyl-(2E)-5-hydroxy-3-methylpent-2-enoate (13.80 g, 86.90 mmol) while ice cooling. The reaction solution was warmed to room temperature and stirred for four hours. After the reaction solution was diluted with ethyl acetate, it was washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=5:1) to obtain the title compound (27.16 g) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.26 (t, J=7.2 Hz, 3H), 2.22 (s, 3H), 2.70 (t, J=7.2 Hz, 2H), 3.54 (t, J=7.2 Hz, 2H), 4.15 (q, J=7.2 Hz, 2H), 5.72 (brs, 1H), 7.54-7.59 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 14.05, 18.22, 30.59, 39.53, 59.48, 117.58, 123.57, 129.61, 129.98, 133.33, 153.61, 155.24, 165.96; IR (KBr)=3064, 2981, 2939, 2903, 2358, 2341, 1713, 1650, 1597, 1500, 1386, 1278, 1222, 1145, 1054, 763, 694 cm−1; HRMS C15H18AgN4O2S (M+Ag+) Calcd: 425.0201, Found: 425.0170.




(2-1) Synthesis of methyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)sulfonyl]pent-2-enoate (Q2a)
This reaction was performed with reference to the literature (Shultz, H. S.; Freyermuth, H. B.; Buc, S. R., J. Org. Chem., 1963, 28(4), 1140-1140.).
About 30% hydrogen peroxide solution (26.7 ml, 235 mmol) solution of hexaammonium heptamolybdate tetrahydrate (2.91 mg, 2.35 mmol) was added to an ethanol (150 ml) solution of methyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)thio]pent-2-enoate (7.53 g, 24.70 mmol) at room temperature. After stirred for at the same temperature for 12 hours, the reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=4:1) to obtain the title compound (8.24 g) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 2.24 (d, J=1.2 Hz, 3H), 2.79-2.83 (m, 2H), 3.71 (s, 3H), 3.88-3.92 (m, 2H), 5.77-5.78 (q, J=1.2 Hz, 1H), 7.60-7.71 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 18.25, 32.44, 50.90, 53.59, 117.67, 124.83, 129.51, 131.30, 132.66, 152.97, 165.99; IR (KBr)=3102, 3075, 2952, 2913, 1703, 1651, 1495, 1439, 1346, 1238, 1160, 1047, 998, 923, 882, 764, 689, 593, 550, 507, 456, 420 cm−1; HRMS C14H16AgN4O4S (M+Ag+) Calcd: 442.9943, Found: 442.9929.




(2-2) Synthesis of ethyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)sulfonyl]pent-2-enoate (Q2b)
This reaction was performed with reference to the literature (Shultz, H. S.; Freyermuth, H. B.; Buc, S. R., J. Org. Chem., 1963, 28(4), 1140-1140.).
About 30% hydrogen peroxide solution (47.4 ml, 418.0 mmol) solution of hexaammonium heptamolybdate tetrahydrate (542 mg, 0.44 mmol) was added to an ethanol (200 ml) solution of ethyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)thio]pent-2-enoate (13.31 g, 41.80 mmol) at room temperature. After stirred for at the same temperature for 12 hours, the reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=4:1) to obtain the title compound (12.65 g) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 1.29 (t, J=7.2 Hz, 3H), 2.24 (d, J=1.2 Hz, 3H), 2.78-2.82 (m, 2H), 3.88-3.92 (m, 2H), 4.17 (q, J=7.2 Hz, 2H), 5.77 (brs, 1H), 7.59-7.71 (m, 5H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 14.22, 18.51, 32.72, 53.93, 59.97, 118.44, 124.95, 129.77, 131.55, 132.88, 152.56, 153.19, 165.81; IR (KBr)=3077, 3008, 2991, 2906, 1698, 1660, 1495, 1342, 1235, 1158, 1045, 877, 764, 689, 589, 550, 508, 454 cm−1; HRMS C15H18AgN4O4S (M+Ag+) Calcd: 457.0100, Found: 457.0133.
Step D2
Synthesis of (2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dien-1-ol




(1-1) Synthesis of methyl-(2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dienoate (Q3a)
This reaction was performed with reference to the literature (Blakemore, P. R.; Cole, W. J.; Kociensky, P. J.; Morley, A., Synlett, 1998, 26-28.).
THF used at this step was distilled by using lithium aluminum hydride. In addition, DME was distilled by using calcium hydride.
0.5M Potassium bis(trimethylsilyl)amide toluene solution (8.48 ml, 4.24 mmol) was added dropwise to a DME (40 ml) solution of methyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)sulfonyl]pent-2-enoate (1.19 g, 3.53 mmol) at −60° C. and the reaction solution was stirred at the same temperature for 30 minutes. Subsequently a THF (5 ml) solution of (2R,3S)-2-methyl-3-[(triethylsilyl)oxy]pentanal (1.63 g, 7.06 mmol) was added dropwise at −78° C. and the reaction solution was stirred for two hours. After the reaction solution was warmed to room temperature, distilled water was added. The reaction solution was diluted with ethyl acetate and washed with brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:diethyl ether=50:1) to obtain the title compound (1.17 g) as a colorless oil. The title compound was determined to be a mixture of E:Z=17:1 by 1H-NMR.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.60 (q, J=8.0 Hz, 6H), 0.87 (t, J=7.2 Hz, 3H), 0.95 (t, J=8.0 Hz, 9H), 0.96 (d, J=6.8 Hz, 3H), 1.35-1.50 (m, 2H), 2.14 (d, J=1.2 Hz, 3H), 2.25-2.31 (m, 1H), 2.82 (d, J=6.4 Hz, 2H), 3.44-3.48 (m, 1H), 3.69 (s, 3H), 5.36 (ddd, J=6.8, 13.6, 15.6 Hz, 1H), 5.51 (dd, J=7.6, 15.2 Hz, 1H), 5.68 (q, J=1.2 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 5.04, 6.78, 9.35, 15.41, 18.57, 26.65, 41.50, 43.86, 50.48, 77.18, 115.38, 124.80, 136.84, 158.86, 166.97; IR (neat)=2958, 2879, 2352, 2330, 1723, 1651, 1435, 1219, 1147, 1013, 740 cm−1; HRMS C19H36AgO3Si (M+Ag+) Calcd: 447.1485, Found: 447.1461; [α]D21 −22.1 (c 1.10, CHCl3).




(1-2) Synthesis of ethyl-(2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dienoate (Q3b)
This reaction was performed with reference to a document (Blakemore, P. R.; Cole, W. J.; Kociensky, P. J.; Morley, A., Synlett, 1998, 26-28.).
THF used at this step was distilled from lithium hydride aluminum. In addition, DME was distilled from calcium hydride.
0.5M Toluene solution (64.2 ml) of potassium bis(trimethylsilyl)amide was added dropwise to a DME (280 ml) solution of ethyl-(2E)-3-methyl-5-[(1-phenyl-1-H-tetrazol-5-yl)sulfonyl]pent-2-enoate (9.0 g, 25.7 mmol) at −60° C. and the reaction solution was stirred at the same temperature for 30 minutes. Subsequently a THF (50 ml) solution of (2R,3S)-2-methyl-3-[(triethylsilyl)oxy]pentanal (12.0 g, 52.1 mmol) was added dropwise at −78° C. and the reaction solution was stirred for one hour. After the reaction solution was warmed to room temperature, distilled water was added. The reaction solution was diluted with ethyl acetate and washed with brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane: diethyl ether=100:1) to obtain the title compound (8.92 g) as a colorless oil. The title compound was determined to be a mixture of E:Z=18:1 by 1H-NMR.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.60 (q, J=8.0 Hz, 6H), 0.87 (t, J=7.2 Hz, 3H), 0.95 (d, J=7.6 Hz, 3H), 0.96 (t, J=8.0 Hz, 9H), 1.27 (t, J=7.2 Hz, 3H), 1.36-1.53 (m, 2H), 2.13 (d, J=1.2 Hz, 3H), 2.26-2.32 (m, 1H), 2.81 (d, J=6.8 Hz, 2H), 3.44-3.48 (m, 1H), 4.14 (q, J=7.2 Hz, 2H), 5.36 (ddd, J=6.8, 13.6, 15.2 Hz, 1H), 5.51 (dd, J=7.6, 15.2 Hz, 1H), 5.67-5.68 (m, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 5.05, 6.77, 9.35, 14.11, 15.37, 18.51, 26.67, 41.50, 43.89, 59.18, 77.20, 115.85, 124.88, 136.78, 158.38, 166.52; IR (neat)=2958, 2879, 2362, 2345, 1719, 1650, 1460, 1218, 1144, 1050, 1013, 740 cm−1; HRMS C20H38AgO3Si (M+Ag+) Calcd: 461.1641, Found: 461.1640; [α]D22 −19.0 (c 2.06, CHCl3).




(2-1) Synthesis of (2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dien-1-ol (Q4)
1M toluene solution (1.76 ml, 1.76 mmol) of diisobutylaluminum hydride was added dropwise to an toluene (6 ml) solution of methyl-(2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dienoate (0.22 g, 0.64 mmol) at −78° C. and the reaction solution was stirred at the same temperature for 30 minutes. The reaction solution was diluted with diethyl ether, followed by addition of a saturated potassium sodium tartrate tetrahydrate aqueous solution (1.0 ml) and was warmed to room temperature and stirred for two hours. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:diethyl ether=8:1) to obtain the title compound (150 mg) as a colorless oil.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.60 (q, J=7.6 Hz, 6H), 0.87 (t, J=7.6 Hz, 3H), 0.95 (d, J=14.0 Hz, 3H), 0.96 (t, J=7.6 Hz, 9H), 1.35-1.50 (m, 2H), 1.65 (brs, 3H), 2.24-2.29 (m, 1H), 2.70 (d, J=6.4 Hz, 2H), 3.45 (dd, J=5.6 Hz, 1H), 4.16 (d, J=7.2 Hz, 2H), 5.32-5.48 (m, 3H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 5.08, 6.85, 9.37, 15.73, 16.08, 26.72, 41.50, 42.82, 59.10 77.39, 123.82, 126.73, 135.25, 138.53; IR (neat)=3330, 2959, 2875, 1671, 1459, 1419, 1009, 740 cm−1; HRMS C18H36AgO2Si (M+Ag+) Calcd: 419.1536, Found: 419.1572; [α]D21 −23.4 (c 1.45, CHCl3).




(2-2) Synthesis of (2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dien-1-ol (Q4)
1M toluene solution of diisobutylaluminum hydride (52.2 ml, 52.2 mmol) was added dropwise to an anhydrous diethyl ether (37.5 ml) solution of ethyl-(2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dienoate (8.92 g, 25.20 mmol) at −78° C. and the reaction solution was stirred at the same temperature for one hour. Methanol (1 ml) and a saturated potassium sodium tartrate tetrahydrate aqueous solution (9.3 ml) were added to the reaction solution, and the mixture was warmed to room temperature and stirred for two hours. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:diethyl ether=8:1) to obtain the title compound (3.84 g) as a colorless oil. 1H-NMR data of the title compound obtained by (2-2) is completely identical to those of the title compound obtained by (2-1).
Step D3
Synthesis of {(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhept-2-en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate




(1) Synthesis of (2R,3R)-3-methyl-3-{(2E,4S,5S)-4-methyl-5-[(triethylsilyl)oxy]hept-2-en-1-yl}oxiran-2-yl)methanol (Q5)
This reaction was performed with reference to the literature (Katsuki, T.; Sharpless, K. B., J. Am. Chem. Soc., 1980, 102, 5976-5978. Gao, Y.; Hanson, R. M. H.; Klunder, J. M.; Ko, S. Y.; Masamune, H.; Sharpless, K. B., ibid., 1987, 109, 5765-5780.).
(i) Distilled anhydrous dichloromethane (22 ml) was added to activated molecular sieves 4A powder (880 mg) under Ar atmosphere and the solution was cooled to −30° C. Subsequently, after diethyl (−)-tartrate (2.01 ml, 11.7 mmol) and titanium tetraisopropoxide (2.32 ml, 7.89 mmol) were added to the reaction solution under stirring and the mixture was stirred for five minutes, a dichloromethane (4 ml) solution of (2E,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dien-1-ol (1.76 g, 5.63 mmol) was added dropwise. After stirred for 30 minutes, 5M tert-butyl hydroperoxide decane solution (2.26 ml, 11.20 mmol) was added dropwise to the reaction solution over 15 minutes. Then the reaction solution was stirred at the same temperature for further 1.5 hours. Distilled water (5 ml) was added to the reaction solution and it was filtered through celite. The filtrate was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=5:1) to obtain the title compound (1.69 g, 90% de) as a colorless oil. The measurement of optical purity of the title compound was performed by converting the title compound to {(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhepta-2en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate (Q7) and determining by HPLC using a chiral column (DAICEL, commercial name CHIRALPAK AD-H, hexane:isopropylalcohol=90:10).
(ii) Distilled anhydrous dichloromethane (12 ml) was added to activated molecular sieves 4A powder (500 mg) under Ar atmosphere and the solution was cooled to −30° C. Subsequently, after isopropyl (−)-tartrate (0.202 ml, 0.96 mmol) and titanium tetraisopropoxide (0.189 ml, 0.640 mmol) were added to the reaction solution under stirring and the mixture was stirred for five minutes, a dichloromethane (3 ml) solution of (2S,5E,7S,8S)-3,7-dimethyl-8-[(triethylsilyl)oxy]deca-2,5-dien-1-ol (1.0 g, 3.20 mmol) was added dropwise. After stirred for 30 minutes, 5M tert-butyl hydroperoxide decane solution (1.28 ml, 6.36 mmol) was added dropwise to the reaction solution over 15 minutes. Then the reaction solution was stirred at the same temperature for further 2 hours. Distilled water (5 ml) was added to the reaction solution and it was filtered through celite. The filtrate was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=5:1) to obtain the title compound (925 mg, 82% de) as a colorless oil. The measurement of optical purity of the title compound was performed by converting the title compound to {(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhepta-2en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate (Q7) and determining by HPLC using a chiral column (DAICEL, commercial name CHIRALPAK AD-H, hexane:isopropylalcohol=90:10).
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.67 (q, J=8.0 Hz, 6H), 0.93 (t, J=7.6 Hz, 3H), 1.02 (d, J=6.8 Hz, 3H), 1.03 (t, J=8.0 Hz, 9H), 1.29 (s, 3H), 1.45-1.58 (m, 2H), 2.23-2.35 (m, 3H), 2.97 (dd, J=4.8, 6.4 Hz, 1H), 3.56 (dt, J=5.6, 6.0 Hz, 1H), 3.63 (dd, J=6.0, 12.0 Hz, 1H), 3.75 (dd, J=4.8, 12.0 Hz, 1H), 5.13 (dt, J=7.2, 15.6 Hz, 1H), 5.57 (dd, J=7.6, 15.6 Hz, 1H); 100 MHz 13C-NMR (CD3OD) δ (ppm) 6.14, 7.43, 9.85, 16.39, 17.05, 27.91, 42.79, 42.99, 61.68, 61.72, 63.68, 78.70, 125.23, 138.18; IR (neat)=3422, 2959, 2877, 1459, 1239, 1103, 1016, 740 cm−1; HRMS C18H36AgO3Si (M+Ag+) Calcd: 435.1485, Found: 435.1492; [α]D21 −15.1 (c 2.14, MeOH) (90% de).




(2) Synthesis of (2R,3R)-3-methyl-3-{(2E,4S,5S)-4-methyl-5-[(triethylsilyl)oxy]hept-2-en-1-yl}oxiran-2-yl)methyl 4-methylbenzenesulfonate (Q6)
Triethylamine (1.86 ml, 12.90 mmol), 4-dimethylaminopyridine (23.7 mg, 0.19 mmol) and p-toluenesulphonyl chloride (493 mg, 2.59 mmol) were added to a dichloromethane (9 ml) solution of (2R,3R)-3-methyl-3-{(2E,4S,5S)-4-methyl-5-[(triethylsilyl)oxy]hept-2-en-1-yl}oxiran-2-yl)methanol (425 mg, 1.29 mmol, 90% de) at room temperature. The reaction solution was stirred at the same temperature for two hours. After the reaction solution was diluted with ethyl acetate, it was washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=15:1) to obtain the title compound (641 mg, 90% de) as a colorless oil. The measurement of optical purity of the title compound was performed by converting the title compound to {(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhept-2-en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate (Q7) and determining by HPLC using a chiral column (DAICEL, commercial name CHIRALPAK AD-H, hexane:isopropylalcohol=90:10).
400 MHz 1H-NMR (CD3OD), δ (ppm) 0.66 (q, j=8.0 Hz, 6H), 0.91 (t, j=7.6 Hz, 3H), 0.99 (d, j=7.2 Hz, 3H), 1.02 (t, J=8.0 Hz, 9H), 1.21 (s, 3H), 1.40-1.56 (m, 2H), 2.15-2.35 (m, 3H), 2.50 (s, 3H), 3.02 (dd, J=4.8, 6.8 Hz, 1H), 3.54 (dt, J=5.2, 6.0 Hz, 1H), 4.10 (dd, J=6.8, 11.2 Hz, 1H), 4.27 (dd, J=4.8, 11.2 Hz, 1H), 5.37 (dt, J=8.0, 15.6 Hz, 1H), 5.53 (dd, J=8.0, 15.6 Hz, 1H), 7.50 (ddd, J=1.0, 2.0, 6.8 Hz, 2H), 7.85 (dd, J=1.6, 6.8 Hz, 2H); 100 MHz 13C-NMR (CD3OD) δ (ppm) 6.11, 7.51, 9.90, 16.44, 17.20, 21.73, 27.87, 42.11, 42.92, 59.45, 61.85, 70.33, 78.54, 124.60, 128.97, 131.07, 134.19, 138.53, 146.44; [α]D21 +2.70 (c 2.10, MeOH).




(3) Synthesis of {(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhept-2-en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate (Q7)
(i) To a THF (2 ml) solution of (2R,3R)-3-methyl-3-{(2E,4S,5S)-4-methyl-5-[(triethylsilyl)oxy]hept-2-en-1-yl}oxiran-2-yl)methyl 4-methylbenzenesulfonate (440 mg, 0.91 mmol, 90% de), 1M hydrochloric acid aqueous solution (0.1 ml) was added at room temperature and the reaction was stirred at the same temperature for one hour. After the reaction solution was diluted with ethyl acetate, it was washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=2:1) to obtain the title compound (334 mg, 90% de) as a colorless oil. The optical purity was determined by HPLC using a chiral column (DAICEL, commercial name CHIRALPAK AD-H, hexane:isopropylalcohol=90:10).
(ii) The title compound ({(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhept-2-en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate) (850 mg, 82% de) was purified by HPLC using a preparative chiral column (DAICEL for fractionation, commercial name CHIRALPAK AD, 20×250 mm, hexane:isopropylalcohol=90:10, flow rate 10 mL/min) and the title compound (634 mg, >99% de) was obtained as a colorless oil. In addition, 13-epoxy isomer thereof (38 mg, >99% de) was obtained as a colorless oil.
Q7: 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.97 (t, J=7.6 Hz, 3H), 1.04 (d, J=6.8 Hz, 3H), 1.21 (s, 3H), 1.29-1.38 (m, 1H), 1.53-1.63 (m, 1H), 2.14-2.30 (m, 3H), 2.50 (s, 3H), 3.03 (dd, J=4.4, 6.8 Hz, 1H), 3.25-3.29 (m, 1H), 4.10 (dd, J=6.8, 11.2 Hz, 1H), 4.28 (dd, J=4.4, 11.2 Hz, 1H), 5.38 (dt, J=6.8, 15.6 Hz, 1H), 5.49 (dd, J=8.0, 15.6 Hz, 1H), 7.50 (dd, J=1.0, 8.4 Hz, 2H), 7.85 (ddd, J=2.0, 2.0, 8.4 Hz, 2H); 100 MHz 13C-NMR (CD3OD) δ (ppm) 10.64, 16.58, 17.10, 21.62, 28.31, 41.96, 44.21, 59.51, 62.01, 70.43, 77.63, 124.85, 129.00, 131.13, 134.15, 138.80, 146.65; IR (neat)=3386, 2976, 2958, 2924, 2502, 1933, 1599, 1454, 1359, 1173, 1095, 967, 866, 782, 667, 554 cm−1; HRMS C19H28NaO5S (M+Na+) Calcd: 391.1555, Found: 391.1550; [α]D2 +2.82 (c 1.04, MeOH). β-epoxy isomer (isomer of Q7): 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.98 (t, J=7.6 Hz, 3H), 1.04 (d, J=6.8 Hz, 3H), 1.21 (s, 3H), 1.27-1.42 (m, 1H), 1.53-1.65 (m, 1H), 2.13-2.31 (m, 3H), 2.50 (s, 3H), 3.03 (dd, J=4.8, 6.8 Hz, 1H), 3.23-3.31 (m, 1H), 4.10 (dd, J=6.8, 11.6 Hz, 1H), 4.28 (dd, J=4.8, 11.6 Hz, 1H), 5.38 (dt, J=7.2, 15.6 Hz, 1H), 5.49 (dd, J=8.0, 15.6 Hz, 1H), 7.50 (dd, J=0.8, 8.0 Hz, 2H), 7.85 (m, 2H).
Step D4
Synthesis of (1R)-1,2-anhydro-3,5-dideoxy-1-[(1R,2S)-2-hydroxy-1-methylbutyl]-4-C-vinyl-D-erythro-pentitol




(1) Synthesis of 5,6:8,9-dianhydro-1,2,4,7-tetradeoxy-4,8-dimethyl-10-O-[(4-methylphenyl)sulfonyl]-D-threo-D-galacto-decitol (Q8)
This reaction was performed with reference to the literature (Wang, Z., -X.; Tu, Y.; Frohn, M.; Zhang, J.-R.; Shi, Y., J. Am. Chem. Soc., 1997, 119, 11224-11235. Wang, Z., -X.; Tu, Y.; Frohn, M.; Zhang, J.-R.; Shi, Y., J. Org. Chem., 1997, 62, 2328-2329.).
(i) {(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhept-2-en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate (2.82 g, 7.64 mmol, 89% de) was dissolved in acetonitrile (80.8 ml) and 0.4 mM ethylenediaminetetraacetic acid disodium salt solution (53.4 ml) of 0.05M sodium tetraborate decahydrate. 1,2:4,5-di-O-isopropylidene-D-erythro-2,3-hexodiuro-2,6-pyranose (1.97 g, 7.64 mmol) was added while ice cooling. Subsequently, a mixed powder of potassium carbonate (12.70 g, 91.80 mmol) and oxone (14.10 g, 22.93 mmol) were added at the same temperature over four hours. The reaction solution was stirred at the same temperature for another hour. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=3:1→2:1) to obtain the title compound (2.57 g, 81% de) as a colorless oil. The optical purity was determined by HPLC using a chiral column (DAICEL, commercial name CHIRALPAK AD-H, hexane:isopropylalcohol=80:20). Subsequently, it was recrystallized with a mixed solvent of hexane-diethyl ether and the title compound (1.52 g) was obtained as a colorless prism crystal of a single diastereomer (>99% de).
(ii) {(2R,3R)-3-[(2E,4S,5S)-5-hydroxy-4-methylhept-2-en-1-yl]-3-methyloxiran-2-yl}methyl 4-methylbenzenesulfonate (700 mg, 1.90 mmol, >99% de) was dissolved in acetonitrile (20.1 ml) and 0.4 mM ethylenediaminetetraacetic acid disodium salt solution (13.3 ml) of 0.05M sodium tetraborate decahydrate. 1,2:4,5-di-O-isopropylidene-D-erythro-2,3-hexodiuro-2,6-pyranose (489 mg, 1.90 mmol) was added while ice cooling. Subsequently, a mixed powder of potassium carbonate (3.15 g, 22.8 mmol) and oxone (3.50 g, 5.71 mmol) were added at the same temperature over four hours. The reaction solution was further stirred at the same temperature for one hour. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=3:1→2:1) to obtain the title compound (331 mg, 88% de) as a colorless oil. The optical purity was determined by HPLC using a chiral column (DAICEL, commercial name CHIRALPAK AD-H, hexane:isopropylalcohol=80:20).
400 MHz 1H-NMR (CD3OD) δ(ppm) 0.98 (d, j=7.2 Hz, 3H), 0.99 (t, J=7.6 Hz, 3H), 1.27-1.36 (m, 1H), 1.32 (s, 3H), 1.48-1.61 (m, 2H), 1.67 (dd, J=6.8, 14.4 Hz, 1H), 1.80 (dd, J=4.8, 14.4 Hz, 1H), 2.50 (s, 3H), 2.71 (dd, J=6.4, 8.0 Hz, 1H), 2.85-2.89 (m, 1H), 3.10 (dd, J=4.4, 6.4 Hz, 1H), 3.57 (dt, J=4.8, 8.0 Hz, 1H), 4.12 (dd, J=6.4, 11.2 Hz, 1H), 4.31 (dd, J=4.4, 11.6 Hz, 1H), 7.44 (dd, J=1.0, 8.0 Hz, 2H), 7.86 (dd, J=2.0, 8.4 Hz, 1H), 7.87 (dd, J=2.0, 8.4 Hz, 1H); 100 MHz 13C-NMR (CD3OD) δ (ppm) 10.55, 10.85, 17.41, 21.62, 28.55, 41.82, 42.36, 55.43, 60.18, 60.63, 61.63, 70.17, 75.15, 129.00, 131.13, 134.04, 146.66; IR (KBr)=3389, 2976, 2957, 2873, 1923, 1598, 1454, 1359, 1188, 1173, 1099, 969, 866, 815, 669, 557, 507 cm−1; HRMS C19H28AgO6S (M+Ag+) Calcd: 491.0658, Found: 491.0638; [α]D23 +42.7 (c 1.00, MeOH) (>99% de).




(2) Synthesis of (1R)-1,2-anhydro-3,5-dideoxy-1-[(1R,2S)-2-hydroxy-1-methylbutyl]-4-C-vinyl-D-erythro-pentitol (Q9)
This reaction was performed with reference to the literature (Fujii, N.; Habashita, H.; Akaji, M.; Nakai, K.; Ibuka, T.; Fujiwara, M.; Tamamura, H.; Yamamoto, Y., J. Chem. Soc., Perkin Trans. 1, 1996, 865-866.).
5,6:8,9-dianhydro-1,2,4,7-tetradeoxy-4,8-dimethyl-10-O-[(4-methylphenyl)sulfonyl]-D-threo-D-galacto-decitol (350 mg, 0.91 mmol) was dissolved in a mixture of acetone (17.5 ml) and DMF (3.5 ml), followed by addition of potassium iodide (528 mg, 3.18 mmol), and the mixture was heated to reflux for two hours. The reaction solution was cooled to 0° C., followed by addition of 4-(dimethylamino)phenyldiphenylphosphine (420 mg, 1.37 mmol) and iodine (100 mg, 0.45 mmol), and the mixture was stirred at the same temperature for 15 minutes. 5% Sodium hydrogen carbonate aqueous solution (3 ml) and 5% carbonic acid sodium thiosulfate aqueous solution (2 ml) were added to the reaction solution and it was stirred at the same temperature for further 10 minutes. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=2.5:1) to obtain the title compound (186 mg) as a colorless oil.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.98 (d, J=7.2 Hz, 3H), 0.99 (t, J=7.6 Hz, 3H), 1.29-1.37 (m, 1H), 1.36 (s, 3H), 1.48-1.61 (m, 2H), 1.73 (dd, J=6.0, 14.0 Hz, 1H), 1.80 (dd, J=6.0, 14.0 Hz, 1H), 2.72 (dd, J=2.4, 7.6 Hz, 1H), 2.95 (dt, J=2.4, 6.0 Hz, 1H), 3.38 (s, 1H), 3.58 (dt, J=4.8, 8.0 Hz, 1H), 5.08 (dd, J=1.6, 10.8 Hz, 1H), 5.29 (dd, J=1.6, 17.6 Hz, 1H), 6.02 (dd, J=10.8, 17.6 Hz, 1H); 100 MHz 13C-NMR (CD3OD) δ (ppm) 10.28, 10.92, 27.88, 28.54, 42.39, 45.54, 55.74, 62.10, 73.17, 75.18, 112.21, 146.27; IR (neat)=3418, 3088, 2970, 2935, 2879, 1647, 1455, 1416, 925 cm−1; HRMS C12H22O3Ag (M+Ag+) Calcd: 321.0620, Found: 321.0667; [α]D24 +13.5 (c 1.67, MeOH) (>99% de).
(2-1) Alternative synthesis of (1R)-1,2-anhydro-3,5-dideoxy-1-[(1R,2S)-2-hydroxy-1-methylbutyl]-4-C-vinyl-D-erythro-pentitol (Q9)
This reaction was performed with reference to the literature (Sarandeses, L. A.; Mourino, A.; Luche, J-L., J. Chem. Soc., Chem. Commun., 1991, 818-820.).
5,6:8,9-dianhydro-1,2,4,7-tetradeoxy-4,8-dimethyl-10-O-[(4-methylphenyl)sulfonyl]-D-threo-D-galacto-decitol (200 mg, 0.53 mmol) was dissolved in a mixed solvent of acetone (5 ml) and DMF (1 ml), followed by addition of potassium iodide (303 mg, 1.83 mmol). The mixture was heated to reflux for two hours. The reaction solution was cooled to room temperature. 5% sodium hydrogen carbonate aqueous solution (3 ml) and 5% carbonic acid sodium thiosulfate aqueous solution (2 ml) were added to the reaction solution and it was stirred at the same temperature for further 10 minutes. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained crude product was used in the next step.
Zinc powder (102, 1.56 mmol) was dissolved in a mixted solution of ethanol (0.5 ml) and water (0.75 ml), followed by addition of copper iodide (99 mg, 0.52 mmol) and the mixed solution was treated with sonication for 5 minutes. An ethanolic solution of the above-obtained crude product (0.5 ml) was added to the reaction solution and it was treated with sonication at same temperature for 1.5 hours. The reaction solution was diluted with ethyl acetate and filtered through celite and washed with distilled water and brine. The organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethylacetate=2.5:1) to obtain the title compound (110 mg) as a colorless oil. 1H-NMR data of title compound by this alternative method are completely identical to those of the title compound obtained by the above (2).
Step D5
Synthesis of (2S,3S,4E,6S,7R,10R)-7,10-dihydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate and (2S,3S,4E,6S,7R,10R)-7-hydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxo-10-[(triethylsilyl)oxy]oxacyclododec-4-en-6-yl acetate




(1) Synthesis of (2S,3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-6,13a-dimethyl-7-[(1E)-1-methylbuta-1,3-dien-1-yl]-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (Q10)
This reaction was performed with reference to the literature (Pine, S. H.; Zahler, R.; Evans, D. A.; Grubbs, R. H., J. Am. Chem. Soc., 1980, 3270-3272.).
(2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-[(E)-2-formyl-1-methyleth-1-en-1-yl]-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (50 mg, 0.09 mmol) was dissolved in a mixed solvent of THF (0.4 ml) and toluene (2.8 ml), and the solution was cooled to −40° C. After addition of pyridine (0.38 ml, 4.73 mmol) and 0.5M toluene solution (1.14 ml, 0.57 mmol) of Tebbe reagent (chlorobis(cyclopentadienyl)-(dimethylaluminum)-methylene titanium), the mixture was stirred at the same temperature for 30 minutes. It was warmed to room temperature and further stirred for one hour. Distilled water (1 ml) was added to the reaction solution, and the reaction solution was diluted with ethyl acetate and washed with distilled water and brine sequentially, and after dried over anhydrous sodium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:diethyl ether=4:1) to obtain the title compound (36.3 mg) as a colorless amorphous substance.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.07 (s, 3H), 0.09 (s, 3H), 0.88 (s, 9H), 0.89 (d, J=6.0 Hz, 3H), 1.35-1.47 (m, 2H), 1.38 (s, 3H), 1.59-1.67 (m, 1H), 1.74 (d, J=0.8 Hz, 3H), 2.01-2.09 (m, 1H), 2.31 (dd, J=10.4, 14.4 Hz, 1H), 2.58 (dd, J=4.4, 14.4 Hz, 1H), 2.54-2.63 (m, 1H), 3.94-4.02 (m, 1H), 4.19 (d, J=9.2 Hz, 1H), 4.97 (d, J=10.4 Hz, 1H), 5.18 (dd, J=1.6, 17.6 Hz, 1H), 5.27 (dd, J=1.6, 17.2 Hz, 1H), 5.40 (dd, J=9.6, 15.2 Hz, 1H), 5.64 (dd, J=9.6, 15.2 Hz, 1H), 5.91 (s, 1H), 6.13 (d, J=10.8 Hz, 1H), 6.54 (dt, J=10.4, 17.2 Hz, 1H), 7.34-7.41 (m, 3H), 7.48-7.52 (m, 2H); 100 MHz 13C-NMR (CDCl3) δ (ppm) −4.63,−4.51, 11.63, 16.72, 17.93, 22.82, 25.72, 31.59, 34.42, 40.24, 44.11, 71.62, 82.07, 83.61, 85.32, 101.21, 118.83, 126.75, 128.32, 129.28, 129.57, 131.26, 131.87, 133.41, 137.69, 137.76, 169.18; IR (KBr)=2957, 2931, 2857, 1735, 1459, 1375, 1275, 1244, 1174, 1078, 1005, 975, 908, 877, 835, 775, 759, 698 cm−1; HRMS C31H46AgO5Si (M+Ag+) Calcd: 633.2165, Found: 633.2189; [α]D23 +19.5 (c 0.90, CHCl3).




(2) Synthesis of (4R,7R,8S,9E,11S,12S)-4,7,8-trihydroxy-7,11-dimethyl-12-[(1E)-1-methylbuta-1,3-dien-1-yl]-oxacyclododec-9-en-2-one (Q11)
Pyridinium p-toluene sulfonate (68.2 mg, 271 μmol) was added to a methanol (1.22 ml) solution of (2S,3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-6,13a-dimethyl-7-[(1E)-1-methylbuta-1,3-dien-1-yl]-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (36.0 mg, 0.07 mmol) and the reaction solution was stirred at room temperature for four days. Distilled water (1 ml) was added to the reaction solution, and the reaction solution was diluted with ethyl acetate and washed with distilled water and brine sequentially, and after dried over anhydrous sodium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:diethyl ether=1:3) to obtain the title compound (18.3 mg) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.92 (d, J=6.9 Hz, 3H), 1.24-1.32 (m, 1H), 1.31 (s, 3H), 1.36-1.72 (m, 3H), 1.76 (d, J=1.0 Hz, 3H), 2.51-2.65 (m, 3H), 3.72-3.77 (m, 1H), 3.82 (d, J=9.6 Hz, 1H), 5.17 (d, J=10.8 Hz, 1H), 5.20 (d, J=11.2 Hz, 1H), 5.28 (dd, J=1.6, 16.8 Hz, 1H), 5.43 (dd, J=10.0, 15.2 Hz, 1H), 5.73 (dd, J=10.0, 15.2 Hz, 1H), 6.12 (d, J=11.6 Hz, 1H), 6.55 (dt, J=10.4, 16.8 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 11.75, 16.52, 24.45, 29.72, 35.57, 38.23, 40.66, 69.23, 73.39, 77.12, 82.45, 119.17, 130.19, 131.61, 131.81, 132.94, 137.18, 172.16; IR (KBr)=3473, 3336, 2960, 2928, 2872, 1729, 1604, 1580, 1460, 1274, 1122, 1028, 959, 743, 420 cm−1; HRMS C18H28AgO5 (M+Ag+) Calcd: 431.0988, Found: 431.0960; [α]D22 +7.01 (c 1.09, CHCl3).




(3) Synthesis of (2S,3S,4E,6S,7R,10R)-7,10-dihydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate (Q12)
Triethylamine (35.6 μl, 246 μmol), acetic anhydride (11.6 μl, 123 μmol) and 4-dimethylaminopyridine (3.0 mg, 24.6 μmol) were added to an anhydrous dichloromethane (2 ml) solution of (4R,7R,8S,9E,11S,12S)-4,7,8-trihydroxy-7,11-dimethyl-12-[(1E)-1-methylbuta-1,3-dien-1-yl]-oxacyclododec-9-en-2-one (40.0 mg, 123 μmol) at 0° C. and the reaction solution was stirred at the same temperature for one hour. The reaction solution was poured into a saturated sodium hydrogen carbonate aqueous solution, and the reaction solution was diluted with ethyl acetate and washed with distilled water and brine sequentially, and after dried over anhydrous sodium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:diethyl ether=1:2) to obtain the title compound (42 mg) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.90 (d, J=6.8 Hz, 3H), 1.21 (s, 3H), 1.25-1.42 (m, 2H), 1.51-1.74 (m, 2H), 1.75 (s, 3H), 2.09 (s, 3H), 2.16 (s, 1H), 2.46-2.67 (m, 3H), 3.54 (d, J=11.2 Hz, 1H), 3.70-3.80 (m, 1H), 5.09 (d, J=8.8 Hz, 1H), 5.17 (d, J=10.8 Hz, 1H), 5.18 (d, J=10.0 Hz, 1H), 5.28 (d, J=16.8 Hz, 1H), 5.61 (dd, J=9.6, 15.2 Hz, 1H), 5.68 (dd, J=9.6, 15.2 Hz, 1H), 6.12 (d, J=10.8 Hz, 1H), 6.55 (dt, J=10.4, 16.8 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 11.75, 16.40, 21.24, 24.57, 29.75, 35.15, 38.26, 40.71, 69.11, 73.35, 78.85, 82.39, 119.19, 125.57, 131.65, 131.79, 132.88, 140.39, 169.61, 172.00; IR (KBr)=3513, 3404, 2970, 2948, 2876, 1734, 1705, 1454, 1429, 1405, 1361, 1248, 1175, 1051, 1023, 968, 921, 652, 550, 508 cm−1; HRMS C20H30O6Na (M+Na+) Calcd: 389.1940, Found: 389.1927; [α]D22 +22.2 (c 1.21, CHCl3).




(4) Synthesis of (2S,3S,4E,6S,7R,10R)-7-hydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxo-10-[(triethylsilyl)oxy]oxacyclododec-4-en-6-yl acetate (Q13)
Triethylamine (260 μl, 1.80 mmol), 4-dimethylaminopyridine (4.26 mg, 0.349 mmol) and chlorotriethylsilane (48 μl, 0.286 mmol) were added to an anhydrous dichloromethane (1.5 ml) solution of (2S,3S,4E,6S,7R,10R)-7,10-dihydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate (30.0 mg, 0.082 mmol) at room temperature and the reaction solution was stirred at the same temperature for five hours. The reaction solution was diluted with ethyl acetate and washed with a saturated sodium hydrogen carbonate aqueous solution, distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=1:2) to obtain the title compound (33 mg) as a white solid.
400 MHz 1H-NMR (CDCl3) δ (ppm) 0.61 (q, J=8.0 Hz, 6H), 0.89 (d, J=6.8 Hz, 3H), 0.97 (t, J=8.0 Hz, 9H), 1.20 (s, 3H), 1.34-1.50 (m, 3H), 1.65-1.70 (m, 1H), 1.72 (d, J=1.2 Hz, 3H), 2.09 (s, 3H), 2.41 (dd, J=1.2, 14.0 Hz, 1H), 2.48 (dd, J=3.6, 14.0 Hz, 1H), 2.49-2.53 (m, 1H), 3.80-3.90 (m, 1H), 4.98 (d, J=10.4 Hz, 1H), 5.07-5.09 (m, 1H), 5.15 (d, J=10.0 Hz, 1H), 5.24 (dd, J=1.6, 16.8 Hz, 1H), 5.58-5.70 (m, 2H), 6.14 (d, J=10.8 Hz, 1H), 6.53 (dt, J=10.4, 16.8 Hz, 1H); 100 MHz 13C-NMR (CDCl3) δ (ppm) 4.70, 6.80, 11.85, 16.47, 21.25, 24.80, 30.30, 35.57, 40.48, 40.70, 70.16, 73.58 78.99, 82.23, 118.57, 125.09, 131.16, 131.99, 133.58, 140.73, 168.67, 169.59; IR (neat)=3316, 2956, 2911, 2875, 1739, 1459, 1370, 1240, 1170, 1089, 1020, 979, 908, 744 cm−1; HRMS C26H44AgO6Si (M+Ag+) Calcd: 587.1958, Found: 587.1915; [α]D26 +34.8 (c 1.50, CHCl3).
Step D6
Synthesis of Pladienolide D and its Analogues




(1) Synthesis of Pladienolide D
This reaction was performed with reference to the literature (Grubbs, R. H. “Handbook of Metathesis”, Wiley-VCH, 2003, v. 2, p 246-292).
(i) (2S,3S,4E,6S,7R,10R)-7,10-dihydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate (10.0 mg, 27.3 μmol) and (1R)-1,2-anhydro-3,5-dideoxy-1-[(1R,2S)-2-hydroxy-1-methylbutyl]-4-C-vinyl-D-erythro-pentitol (17.6 mg, 81.9 μmol) were dissolved in anhydrous dichloromethane (1 ml) under Ar atmosphere, followed by addition of the second generation Hoveyda-Grubbs catalyst; [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(O-isopropoxyphenylmethylene)ruthenium (0.85 mg, 1.4 μmol). After the reaction solution was warmed to reflux for one hour, it was cooled to room temperature and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=2.5:1→1:2→0:1) to obtain the title compound (9.5 mg) as a white amorphous.
(ii) (2S,3S,4E,6S,7R,10R)-7,10-dihydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate (10.0 mg, 27.3 μmol) and (1R)-1,2-anhydro-3,5-dideoxy-1-[(1R,2S)-2-hydroxy-1-methylbutyl]-4-C-vinyl-D-erythro-pentitol (11.7 mg, 54.6 μmol) were dissolved in anhydrous dichloromethane (2.5 ml) under Ar atmosphere, followed by addition of the second generation Grubbs catalyst; [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)-tricyclohexylphospine)ruthenium (1.16 mg, 1.4 μmol). After the reaction solution was heated to reflux for one hour, it was cooled to room temperature and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=2.5:1→1:2→0:1) to obtain the title compound (9.5 mg) as a white amorphous.
600 MHz 1H-NMR (CD3OD) δ (ppm) 0.93 (d, J=6.8 Hz, 3H), 0.94 (d, J=7.0 Hz, 3H), 0.98 (t, J=7.4 Hz, 3H), 1.23 (s, 3H), 1.30 (m, 1H), 1.38 (s, 3H), 1.40 (m, 1H), 1.42 (m, 1H), 1.54 (m, 2H), 1.62 (m, 1H), 1.66 (m, 1H), 1.70 (dd, J=6.3, 14.1 Hz, 1H), 1.82 (d, J=0.9 Hz, 3H), 1.91 (dd, J=5.5, 14.0 Hz, 1H), 2.10 (s, 3H), 2.57 (m, 2H), 2.62 (ddq, J=6.8, 9.8, 10.6 Hz, 1H), 2.71 (dd, J=2.2, 7.9 Hz, 1H), 2.93 (ddd, J=2.2, 6.3, 6.3 Hz, 1H), 3.57 (ddd, J=4.5, 4.5, 8.3 Hz, 1H), 3.83 (m, 1H), 5.09 (d, J=9.8 Hz, 1H), 5.11 (d, J=10.6 Hz, 1H), 5.61 (dd, J=9.9, 15.2 Hz, 1H), 5.75 (dd, J=9.8, 15.2 Hz, 1H), 5.92 (d, J=15.3 Hz, 1H), 6.18 (d, J=11.0 Hz, 1H), 6.57 (dd, J=11.0, 15.3 Hz, 1H); 150 MHz 13C-NMR (CD3OD) δ (ppm) 10.5, 10.8, 12.0, 16.9, 21.1, 24.2, 28.6, 28.8, 30.5, 37.5, 40.1, 41.8, 42.6, 46.0, 56.0, 62.5, 70.4, 73.1, 74.1, 75.3, 80.3, 84.2, 123.7, 127.1, 131.8, 133.8, 141.6, 143.2, 171.7, 172.2; IR (KBr)=3438, 2968, 2939, 2879, 1733, 1720, 1458, 1371, 1244, 1176, 1021, 977, 832, 789, 747, 612, 551, 474, 433, 420, 409 cm−1; HRMS: C30H48NaO9 (M+Na+), Calcd: 575.3196, Found: 575.3168; [α]D25−14.7 (c 1.10, MeOH).




(2) Synthesis of 3-[(triethylsilyl)oxy]-pladienolide D
This reaction was performed with reference to the literature (Grubbs, R. H. “Handbook of Metathesis”, Wiley-VCH, 2003, v. 2, p 246-292).
(2S,3S,4E,6S,7R,10R)-7-hydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxo-10-[(triethylsilyl)oxy]oxacyclododec-4-en-6-yl acetate (8.60 mg, 17.9 μmol) and (1R)-1,2-anhydro-3,5-dideoxy-1-[(1R,2S)-2-hydroxy-1-methylbutyl]-4-C-vinyl-D-erythro-pentitol (8.67 mg, 40.5 μmol) were dissolved in anhydrous dichloromethane (1.8 ml) under Ar atmosphere, followed by addition of the second generation Grubbs catalyst; [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)-tricyclohexylphospine)ruthenium (0.76 mg, 0.9 μmol). After the reaction solution was heated to reflux for 1.5 hours, it was cooled to room temperature and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=3:1→2:1→1:1→0:1) to obtain the title compound (11.9 mg) as a colorless oil.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.68 (q, J=7.6 Hz, 6H), 0.93 (d, J=6.8 Hz, 3H), 0.94 (d, J=7.2 Hz, 3H), 0.98 (t, J=7.2 Hz, 3H), 1.03 (t, J=7.6 Hz, 9H), 1.21 (s, 3H), 1.26-1.31 (m, 1H), 1.32-1.36 (m, 2H), 1.38 (s, 3H), 1.38-1.42 (m, 1H), 1.46-1.60 (m, 3H), 1.70 (dd, J=6.4, 14.0 Hz, 1H), 1.80 (d, J=1.2 Hz, 3H), 1.91 (dd, J=5.6, 14.4 Hz, 1H), 2.10 (s, 3H), 2.43 (dd, J=4.8, 14.0 Hz, 1H), 2.56 (dd, J=3.2, 14.0 Hz, 1H), 2.58-2.66 (m, 1H), 2.71 (dd, J=2.4, 8.0 Hz, 1H), 2.94 (dt, J=2.4, 6.4 Hz, 1H), 3.57 (dt, J=4.4, 8.0 Hz, 1H), 3.90-4.01 (m, 1H), 4.97 (d, J=10.8 Hz, 1H), 5.06 (d, J=9.6 Hz, 1H), 5.61 (dd, J=10.0, 15.2 Hz, 1H), 5.75 (dd, J=9.6, 15.2 Hz, 1H), 5.91 (d, J=15.2 Hz, 1H), 6.18 (dd, J=1.2, 11.2 Hz, 1H), 6.57 (dd, J=11.2, 15.2 Hz, 1H); HRMS: C36H62O9NaSi (M+Na+), Calcd: 689.4061, Found: 689.4044.




(3) Synthesis of (3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-[(1E,3E)-5-hydroxy-1,5-dimethyl-7-phenylhepta-1,3-dien-1-yl]-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (Q15)
This reaction was performed with reference to the literature (Grubbs, R. H. “Handbook of Metathesis”, Wiley-VCH, 2003, v. 2, p 246-292).
(3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-6,13a-dimethyl-7-[(1E)-1-methylbuta-1,3-dien-1-yl]-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (15.0 mg, 28.5 μmol) and 3-methyl-5-phenylpent-1-en-3-ol (15.1 mg, 85.5 μmol) were dissolved in anhydrous dichloromethane (1.0 ml) under Ar atmosphere, followed by addition of the second generation Grubbs catalyst; [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)-tricyclohexylphospine)ruthenium (2.0 mg, 2.4 μmol). The reaction solution was stirred at room temperature for 12 hours. Furthermore, the reaction solution was heated to reflux for five hours. The reaction solution was cooled to room temperature and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; heptane:ethyl acetate=6:1→3:1) to obtain the title compound (14.1 mg) as a colorless oil. The title compound was determined to be a mixture of α benzylidene acetal and β benzylidene acetal in a ratio of 1:3 by 1H-NMR.
Q15β: 400 MHz 1H-NMR (CDCl3) δ (ppm) 0.08 (s, 3H), 0.10 (s, 3H), 0.89 (s, 9H), 0.93 (d, J=6.8 Hz, 3H), 1.24-1.28 (m, 1H), 1.35 (s, 3H), 1.37 (s, 3H), 1.39-1.47 (m, 1H), 1.69 (t, J=11.6 Hz, 1H), 1.78 (s, 3H), 1.80-1.94 (m, 2H), 1.99-2.04 (m, 1H), 2.32 (dd, J=6.0, 14.4 Hz, 1H), 2.56-2.69 (m, 4H), 3.94-4.05 (m, 1H), 4.32 (d, J=10.0 Hz, 1H), 5.01 (d, J=10.8 Hz, 0.6H), 5.02 (d, J=10.8 Hz, 0.4H), 5.46 (dd, J=9.6, 15.2 Hz, 1H), 5.86 (dd, J=15.2 Hz, 1H), 5.84-5.92 (m, 1H), 6.10 (s, 1H), 6.15 (d, J=10.8 Hz, 1H), 6.44-6.52 (m, 1H), 7.14-7.20 (m, 3H), 7.20-7.27 (m, 3H), 7.30-7.39 (m, 2H), 7.47-7.52 (m, 2H); LRMS C41H58NaO6Si (M+Na+) Calcd: 697.39, Found: 697.44.
REFERENCE EXAMPLES
Synthesis of (3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-6,13a-dimethyl-7-[(1E)-1-methylbuta-1,3-dien-1-yl]-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (Q10b)




(1) Synthesis of 3,21-bis{[tert-butyl(dimethyl)silyl]oxy}-pladienolide B (Q16)
Imidazole (1.66 g, 24.4 mmol) and tert-butyldimethylsilyl chloride (3.68 g, 24.4 mmol) were added to a DMF (21.8 ml) solution of pladienolide B (2.18 g, 2.44 mmol, 60% purity) at room temperature and it was stirred at the same temperature for two hours. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=4:1) to obtain the title compound (1.68 g) as a white amorphous. LRMS C42H76NaO8Si2 (M+Na+) Calcd: 787.50, Found: 787.62.




(2) Synthesis of 3,21-bis{[tert-butyl(dimethyl)silyl]oxy}-pladienolide A (Q17)
Potassium carbonate (304 mg, 2.20 mmol) was added to a methanol (25.0 ml) solution of 3,21-bis{[tert-butyl(dimethyl)silyl]oxy}-pladienolide B (1.68 g, 2.20 mmol) at room temperature. After the reaction solution was stirred at room temperature for 1.5 hours, it was poured into brine, which was then extracted with ethyl acetate. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; heptane:ethyl acetate=3:1) to obtain the title compound (1.55 g) as a colorless oil.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.07 (s, 12H), 0.81 (t, J=7.6 Hz, 3H), 0.85 (d, J=7.2 Hz, 6H), 0.91 (s, 18H), 1.08 (d, J=6.4 Hz, 3H), 1.25 (s, 3H), 1.22-1.72 (m, 9H), 1.73 (s, 3H), 2.36 (dd, J=4.8, 13.6 Hz, 1H), 2.40-2.50 (m, 1H), 2.50 (dd, J=3.2, 13.6 Hz, 1H), 2.50-2.60 (m, 1H), 2.61 (dd, J=2.5, 8.4 Hz, 1H), 2.72 (dt, J=2.2, 6.0 Hz, 1H), 3.68 (d, J=9.6 Hz, 1H), 3.68-3.76 (m, 1H), 3.85-3.95 (m, 1H), 4.88 (d, J=12.4 Hz, 1H), 5.38 (dd, J=10.0, 15.2 Hz, 1H), 5.62 (dd, J=8.4, 15.2 Hz, 1H) 5.71 (dd, J=10.0, 15.2 Hz, 1H), 6.08 (brd, J=10.8 Hz, 1H), 6.32 (dd, J=10.8, 15.2 Hz, 1H); LRMS C40H74NaO7Si2 (M+Na+) Calcd: 745.49, Found: 745.53.




(3) Synthesis of 6,7-O-benzylidene-3,21-bis{[tert-butyl(dimethyl)silyl]oxy}-pladienolide A (Q18)
Benzaldehyde dimethylacetal (3.21 ml, 21.4 mmol) and pyridinium p-toluene sulfonate (53.8 mg, 0.214 mmol) were added to an anhydrous dichloromethane (16 ml) solution of 3,21-bis{[tert-butyl(dimethyl)silyl]oxy}-pladienolide A (1.55 g, 2.14 mmol). The reaction solution was stirred at room temperature for 28 hours. The reaction solution was poured into a saturated sodium hydrogen carbonate aqueous solution, which was then extracted with dichloromethane. After the organic layer was washed with water and brine sequentially, it was dried over anhydrous magnesium sulfate. After the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica gel 60N, granular, neutral, 0.040 mm-0.100 mm; heptane:ethyl acetate=20:1→10:1) to obtain the title compound (1.60 g) as a white amorphous. The title compound was determined to be a mixture of α benzylidene acetal and β benzylidene acetal in a ratio of 1:3.2 by 1H-NMR.
Compound Q18β: 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.08 (s, 6H), 0.11 (s, 3H), 0.13 (s, 3H), 0.82 (t, J=7.6 Hz, 3H), 0.86 (t, 3H), 0.91 (s, 18H), 0.92 (d, J=6.0 Hz, 3H), 1.08 (d, J=6.8 Hz, 3H), 1.21-1.31 (m, 1H), 1.34 (s, 3H), 1.35-1.60 (m, 5H), 1.64-1.72 (m, 1H), 1.72-1.82 (m, 1H), 1.76 (s, 3H), 1.90-2.00 (m, 1H), 2.25 (dd, J=10.0, 14.8 Hz, 1H), 2.42-2.54 (m, 1H), 2.58-2.65 (m, 2H), 2.66-2.75 (m, 2H), 3.70-3.76 (m, 1H), 4.00-4.10 (m, 1H), 4.37 (d, J=9.6 Hz, 1H), 4.96 (d, J=10.4 Hz, 1H), 5.50 (dd, J=9.6, 15.2 Hz, 1H), 5.64 (dd, J=9.6, 15.2 Hz, 1H), 6.00 (dd, J=10.0, 14.8 Hz, 1H), 6.08 (s, 1H,), 6.09 (d, 9.6 Hz, 1H), 6.33 (dd, J=10.4, 14.8 Hz, 1H), 7.32-7.40 (m, 3H), 7.44-7.50 (m, 2H); LRMS C47H78NaO7Si2 (M+Na+) Calcd: 833.52, Found: 833.61.




(4) Synthesis of (3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-{(1E,5S)-6-[(2R,3R)-3-((1S,2S)-2-{[tert-butyl(dimethyl)silyl]oxy}-1-methylbutyl)oxiran-2-yl]-3,4-dihydroxy-1,5-dimethylhex-1-en-}-yl′-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (Q19)
6,7-O-benzylidene-3,21-bis{[tert-butyl(dimethyl)silyl]oxy}-pladienolide A (1.60 g, 1.97 mmol) was dissolved in THF (35 ml) and water (10 ml), followed by addition of osmium tetraoxide (1.25 ml, 0.197 mmol, 4% aqueous solution) and 4-methylmorpholine-4-oxide (0.4 ml, 2.17 mmol, 50% aqueous solution) at room temperature, and the mixture was stirred at the same temperature for 24 hours. Subsequently sodium sulfite (0.498 g, 3.94 mmol) was added to the reaction solution, and the mixture was stirred at the same temperature for another hour. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=2:1) to obtain the title compound (1.46 g) as a colorless oil. LRMS C47H80NaO9Si2 (M+Na+) Calcd: 867.52, Found: 868.68.




(5) Synthesis of (5R)-4,5-anhydro-5-((1S,2S)-2-{[tert-butyl(dimethyl)silyl]oxy}-1-methylbutyl)-2,3-dideoxy-2-methyl-L-erythro-pentose (Q20) and (3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-[(E)-2-formyl-1-methyleth-1-en-1-yl]-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (P18b)
(3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-{(1E,5S)-6-[(2R,3R)-3-((1S,2S)-2-{[tert-butyl(dimethyl)silyl]oxy}-1-methylbutyl)oxiran-2-yl]-3,4-dihydroxy-1,5-dimethylhex-1-en-1-yl}-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (1.46 g, 1.73 mmol) was dissolved in THF (30 ml) and water (7.5 ml), followed by addition of sodium metaperiodate (1.11 g, 5.19 mmol) at room temperature, and the mixture was stirred at the same temperature for 1.5 hours. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=10:1→8:1→5:1) to obtain the title compound Q20 (0.485 g) as a colorless oil and to obtain the title compound P18b (0.803 g) as a colorless oil. The title compound P18b was determined to be a mixture of α benzylidene acetal and β benzylidene acetal in a ratio of 1:3.2 by 1H-NMR.
Compound Q20: 400 MHz 1H-NMR (CDCl3) δ (ppm) 0.06 (s, 6H), 0.81 (t, J=7.6 Hz, 3H), 0.87 (t, J=6.8 Hz, 3H), 0.89 (s, 9H), 1.20 (dd, J=0.8, 7.6 Hz, 3H), 1.28-1.39 (m, 1H), 1.42-1.56 (m, 3H), 2.05 (ddd, J=4.4, 8.0, 13.6 Hz, 1H), 2.52-2.63 (m, 1H), 2.67 (dd, J=2.4, 8.0 Hz, 1H), 2.72-2.80 (m, 1H), 3.67-3.76 (m, 1H), 9.67 (d, J=0.8 Hz, 1H); LRMS C17H35NaO3Si (M+H+) Calcd: 315.24, Found: 315.06.
Compound Q18bβ: 400 MHz 1H-NMR (CDCl3) δ (ppm) 0.09 (s, 3H), 0.10 (s, 3H), 0.89 (s, 9H), 0.98 (d, J=6.8 Hz, 3H), 1.35 (s, 3H), 1.34-1.50 (m, 2H), 1.68-1.78 (m, 1H), 1.92-2.04 (m, 1H), 2.18 (brs, 3H), 2.37 (dd, J=9.6, 14.8 Hz, 1H), 2.60 (dd, J=4.0, 14.8 Hz, 1H), 2.60 (dd, J=4.0, 14.8 Hz, 1H), 2.60-2.70 (m, 1H), 3.92-4.02 (m, 1H), 4.31 (d, J=10.0 Hz, 1H), 4.94 (d, J=10.4 Hz, 1H), 5.46 (dd, J=9.6, 15.2 Hz, 1H), 5.92 (dd, J=9.6, 15.2 Hz, 1H), 6.07 (dd, J=1.6, 7.6 Hz, 1H), 6.11 (s, 1H), 7.31-7.42 (m, 3H), 7.45-7.54 (m, 2H), 10.05 (d, J=7.6 Hz, 1H); LRMS C30H44NaO6Si (M+Na+) Calcd: 551.28, Found: 551.29.




(6) Synthesis of (3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-6,13a-dimethyl-7-[(1E)-1-methylbuta-1,3-dien-1-yl]-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (Q10b)
Potassium tert-butoxide (38.2 mg, 0.341 mmol) was added to an anhydrous THF (3 ml) solution of methyltriphenylphosphonium iodide (100 mg, 0.247 mmol) at room temperature, and it was stirred at room temperature for 30 minutes. Subsequently, a THF (3 ml) solution of (3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-[(E)-2-formyl-1-methyletha-1-en-1-yl]-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (150 mg, 0.284 mmol) was added dropwise to this reaction solution at room temperature and the reaction solution was stirred for one hour. The reaction solution was diluted with ethyl acetate and washed with distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate and the drying agent was filtered off, the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=20:1) to obtain the title compound (44 mg) as a white solid. The title compound was determined to be a mixture of α benzylidene acetal and β benzylidene acetal in a ratio of 1:3.2 by 1H-NMR.
Q10bβ: 400 MHz 1H-NMR (CDCl3) δ (ppm) 0.08 (s, 3H), 0.10 (s, 3H), 0.89 (s, 9H), 0.92 (d, J=6.8 Hz, 3H), 1.28-1.50 (m, 2H), 1.34 (s, 3H), 1.65-1.74 (m, 1H), 1.75 (brs, 3H), 1.98-2.08 (m, 1H), 2.32 (dd, J=10.0, 14.4 Hz, 1H), 2.58 (dd, J=4.0, 14.4 Hz, 1H), 2.58-2.70 (m, 1H), 3.92-4.02 (m, 1H), 4.32 (d, J=10.0 Hz, 1H), 5.00 (d, J=10.8 Hz, 1H), 5.18 (d, 10.0 Hz, 1H), 5.27 (d, J=16.8 Hz, 1H), 5.46 (dd, J=9.6, 15.2 Hz, 1H), 5.89 (dd, J=10.0, 15.2 Hz, 1H), 6.09 (s, 1H), 6.14 (d, J=10.8 Hz, 1H), 6.55 (dt, J=10.8, 16.8 Hz, 1H), 7.28-7.41 (m, 3H), 7.44-7.53 (m, 2H); LRMS C31H46NaO5Si (M+Na+) Calcd: 549.30, Found: 549.26.
(6-1) Alternative synthesis of (3aS,4E,6S,7S,11R,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-6,13a-dimethyl-7-[(1E)-1-methylbuta-1,3-dien-1-yl]-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (Q10b)
The reaction was performed with reference to the literature (Ager, D. J., Synthesis, 1984, 384-398. Hudrlik, P. F.; Peterson, D., J. Am. Chem. Soc., 1975, 97, 1464-1468.).
Magnesium trimethylsilylmethylchloride 1.5M diethyl ether solution (1.33 ml, 2.0 mmol) was added to a diethyl ether solution (20 ml) of (2S,3aS,4E,6S,7S,13aR)-11-{[tert-butyl(dimethyl)silyl]oxy}-7-[(E)-2-formyl-1-methyleth-1-en-1-yl]-6,13a-dimethyl-2-phenyl-3a,6,7,10,11,12,13,13a-octahydro-9H-[1,3]dioxolo[4,5-f]oxacyclododecin-9-one (510 mg, 0.965 mmol) and stirred at the same temperature for 30 minutes. The reaction solution was diluted with diethyl ether, followed by addition of water and sequentially washed with ammonium chloride aqueous solution and brine. The organic layer was dried over anhydrous magnesium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure.
The obtained crude product was dissolved in THF (15 ml), followed by addition of sulfuric acid (6 drops) at room temperature and the solution was stirred for 1 hour at the same temperature. The reaction solution was diluted with ethyl acetate and washed with water and brine. The organic layer was dried over anhydrous magnesium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane:ethyl acetate=30:1) to obtain the title compound (312 mg) as colorless oil. 1H-NMR data of title compound by this alternative method are completely identical to those of the title compound obtained by the above (6).
Reference Example 2




Synthesis of (2S,3S,4E,6S,7R,10R)-10-{[tert-butyl(dimethyl)silyl]oxy}-2-{(1E,5S)-6-[(2R,3R)-3-((1S, 2S)-2-{tert-butyl(dimethyl)silyl]oxy)-1-methylbutyl}oxiran-2-yl}-3,4-dihydroxy-1,5-dimethylhexa-1-en-1-yl′-7-hydroxy-3,7-dimethyl-12-oxooxacyclododeca-4-en-6-yl acetate (R6)
3,21-bis{[tert-butyl(dimethyl)silyl]oxy}-pladienolide B (60 mg, 0.078 mmol) was dissolved in THF (1 ml) and water (1 ml), followed by addition of osmium tetraoxide (0.199 ml, 0.016 mmol, 2% aqueous solution) and 4-methylmorpholine-4-oxide (18 μml, 0.078 mmol, 50% aqueous solution) at room temperature. The solution was stirred for 24 hours at the same temperature. Then sodium sulfite (19.8 mg, 0.156 mmol) was added to the reaction solution and further stirred for 1 hour at the same temperature. The reaction solution was diluted by ethyl acetate and washed with the distilled water and brine. The organic layer was dried over anhydrous sodium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromotography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=1:1) to obtain the title compound (67.6 mg) as colorless oil. The title compound was determined as a mixture of diastereomers (1:3).
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.11 (s, 12H), 0.85-0.89 (m, 3H), 0.92-0.98 (m, 6H), 0.95 (s, 9H), 0.96 (s, 9H), 0.99 (d, J=6.0 Hz, 0.75H), 1.11 (d, J=6.0 Hz, 2.25H), 1.21 (s, 3H), 1.24-1.74 (m, 9.25H), 1.73 (s, 2.25H), 1.79 (s, 0.75H), 1.84-1.95 (m, 0.75H), 2.10 (s, 3H), 2.36-2.45 (m, 1H), 2.51-2.63 (m, 2H), 2.61 (dd, J=2.0, 8.0 Hz, 0.75H), 2.69 (dd, J=2.0, 8.0 Hz, 0.25H), 2.72-2.84 (m, 1H), 3.28 (dd, J=5.6, 5.6 Hz, 0.75H), 3.45 (dd, J=2.8, 7.2 Hz, 0.25H), 3.74-3.82 (m, 1H), 3.90-4.00 (m, 1H), 4.26-4.39 (m, 1H), 4.87-4.93 (1H, covered with CD3OD), 4.96 (d, J=9.6 Hz, 0.25H), 5.06 (d, J=9.6 Hz, 0.75H), 5.54-5.68 (m, 2H), 5.75 (dd, J=9.6 Hz, 15.2 Hz, 1H); LRMS C42H78NaO10Si2 (M+Na+) Calcd: 821.50, Found: 821.26.
Reference Example 3




Synthesis of (5R)-4,5-anhydro-5-((1S,2S)-2-{[tert-butyl(dimethyl)silyl]oxy}-1-methylbutyl)-2,3-dideoxy-2-methyl-L-erythro-pentose (Q20) and (2S,3S,4E,6S,7R,10R)-10-{[tert-butyl(dimethyl)silyl]oxy}-7-hydroxy-3,7-dimethyl-2-[(1E)-1-methyl-3-oxoprop-1-en-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate (R4)
(2S,3S,4E,6S,7R,10R)-10-{[tert-butyl(dimethyl)silyl]oxy}-2-[(1E,55)-6-[(2R,3R)-3-((1S,2S)-2-{[tert-butyl(dimethyl)silyl]oxy}-1-methylbutyl)oxiran-2-yl]-3,4-dihydroxy-1,5-dimethylhex-1-en-1-yl}-7-hydroxy-3,7-dimethyl-12-oxooxacyclododeca-4-en-6 yl acetate (67.6 mg 0.0847 mmol) was dissolved in THF (1.5 ml) and water (1.5 ml), followed by addition of sodium metaperiodate (181 mg, 0.847 mmol) at room temperature. The reaction solution was stirred for 1 hour at the same temperature. The reaction solution was diluted by distilled water and brine. After the organic layer was dried over anhydrous sodium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromotography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=20:1→2:1) to obtain the title compound R4 (19.3 mg) as colorless oil and the title compound Q20 (36.0 mg) as colorless oil. 1H-NMR data of title compound are completely identical to those of the compound Q20 obtained by Reference Example 1 (5).
R4: 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.12 (s, 3H), 0.14 (m, 3H), 0.95 (s, 9H), 1.00 (d, J=6.8 Hz, 3H), 1.24 (s, 3H), 1.23-1.84 (m, 4H), 2.10 (s, 3H), 2.22 (d, J=1.2 Hz, 3H), 2.44 (dd, J=4.8, 13.6 Hz, 1H), 2.55-2.66 (m, 2H), 3.93-4.03 (m, 1H), 4.93 (d, J=10.8 Hz, 1H), 5.06 (d, J=9.6, 1H), 5.64 (dd, J=10.0, 15.2 Hz, 1H), 5.80 (dd, J=9.6, 15.2 Hz, 1H), 6.08 (brd, J=8.0 Hz, 1H), 10.06 (d, J=8.0 Hz, 1H); LRMS C25ClH42OSi (M+Cl−) Calcd: 517.24, Found: 7.09.
Reference Example 4




Synthesis of tert-butyl[((1S,2S)-1-ethyl-2{(2R,3R)-3-[(2S)-2-methylbut-3-en-1-yl]oxiran-2-yl}propyl)oxy]dimethylsilane (R5)
This reaction was performed with reference to the literature (Matusbara, S.; Sugihara, M.; Utimoto, K., Synlett, 1998, 97, 313-315.).
Boron trifluoride dimethy ether complex was added to THF solution (6 ml) of 10% wt of tetrahydrofuran suspension (4.56 g, 2.0 mmol) of Nysted reagent ([cyclo-dibromodi-μ-methylene(μ-tetrahydrofuran)trizinc]) at 0° C. and stirred for 5 minutes at the same temperature. THF solution (2 ml) of ((5R)-4,5-anhydro-5-((1S,2S)-2-{[tert-butyl(dimethyl)silyl]oxy}-1-methylbutyl)-2,3-dideoxy-2-methyl-L-erythro-pentose (315 mg, 0.01 mmol) was added to the reaction solution. After the solution was warmed to room temperature, it was stirred for 3 hours. 1M of Hydrochloric acid (3 ml) was added to the reaction solution and it was diluted with hexane, sequentially washed with distilled water and brine. It was dried over anhydrous magnesium sulfate, the drying agent was filtered off and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromotography (Kanto, commercial name Silica Gel 60N, 40-100 μm; heptane:ethyl acetate=50:1→5:1) to obtain the title compound (9.77 mg) as colorless oil.
R4: 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.13 (s, 6H), 0.88 (d, J=7.6 Hz, 3H), 0.94 (d, J=7.6 Hz, 3H), 0.96 (s, 9H), 1.10 (d, J=6.8 Hz, 3H), 1.30-1.42 (m, 1H), 1.48-1.64 (m, 4H), 2.34-2.50 (m, 1H), 2.72 (dd, J=2.4, 8.0 Hz, 1H), 2.75-2.85 (m, 1H), 3.69-3.82 (m, 1H) 5.01 (brd, J=10.8 Hz, 1H), 5.08 (brd, J=17.2 Hz, 1H) 5.72-5.86 (m, 1H); LRMS C18H36NaO2Si (M+Na+) Calcd: 335.24, Found: 335.05.
Reference Example 5




Synthesis of (2S,3S,4E,6S,7R,10R)-7-hydroxy-3,7-dimethyl-2-[(1E)-1-methylbuta-1,3-dien-1-yl]-12-oxo-10-{[tert-butyl(dimethyl)silyl]oxy}oxacyclododec-4-en-6-yl acetate (R6)
This reaction was performed with reference to the literature (Pine, S. H.; Zahler, R.; Evans, D. A.; Grubbs, R. H., J. Am. Chem. Soc., 1980, 3270-3272.).
THF (0.8 ml) of (2S,3S,4E,6S,7R,10R)-10-{tert-butyl(dimethyl)silyl]oxy}-7-hydroxy-3,7-dimethyl-2-[(1E)-1-methyl-3-oxoprop-1-en-1-yl]-12-oxooxacyclododec-4-en-6-yl acetate (86.9 mg, 0.18 mmol) and toluene (6.1 ml) was dissolved as a mixed solvent and it was cooled to −40° C. Pyridine (0.15 ml, 1.89 mmol) and 0.5 M toluene solution of Tebbe reagent (chlorobis(cyclopentadienyl)-(dimethylaluminium)-(methylenetitanium) were added to it and the reaction solution was stirred for 30 minutes at the same temperature. The reaction solution was warmed to −20° C. and stirred for further 30 minutes. Distilled water was added to the reaction solution and it was diluted with ethyl acetate and washed sequentially with distilled water and brine. After the reaction solution was dried over anhydrous sodium sulfate, the drying agent was filtered off and was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name; Silica Gel 60, 230-400 mesh; hexane; diethyl ether=4:1) to obtain the title compound (41 mg) as a colorless amorphous.
400 MHz 1H-NMR (CDCL3) δ (ppm) 0.06 (s, 3H), 0.07 (s, 3H), 0.89 (d, J=6.4 Hz, 3H), 0.97 (s, 9H), 1.21 (s, 3H), 1.28-1.50 (m, 3H), 1.62-1.70 (m, 1H), 1.72 (brs, 3H), 2.10 (s, 3H), 2.39 (dd, J=4.4, 14.0 Hz, 1H), 2.46 (dd, J=3.6, 14.0 Hz, 1H), 2.44-2.55 (m, 1H), 3.80-3.90 (m, 1H), 4.97 (d, J=10.8 Hz, 1H), 5.07-5.09 (m, 1H), 5.15 (dd, J=1.6, 10.0 Hz, 1H), 5.24 (dd, J=1.6, 16.8 Hz, 1H), 5.56-5.72 (m, 2H), 6.14 (d, J=10.8 Hz, 1H), 6.53 (dt, J=10.0, 16.8 Hz, 1H); LRMS C26H44NaO6Si (M+Na+) Calcd: 503.28, Found: 503.21.
Reference Example 6




Synthesis of 4,5-anhydro-3,6,8,9-tetradeoxy-6-methyl-2-C-methyl-2,7-bis-O-(triethylsilyl)-L-glycero-D-gluco-nonose (R8)
3,16,21-tris-[(triethylsilyl)oxy]-pladienolide D (50 mg, 55.9 μl; Example 46 of WO 03/099813) was dissolved in dichloromethane. The reaction solution was cooled to −78° C. Ozone (flow rate 2 l/min, voltage 90 V) was blown into the reaction solution for 10 minutes during stirring. After dimethyl sulfide (10.4 mg, 0.168 mmol) was added, the reaction solution was warmed to room temperature, stirred for 1 hour and was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Kanto, commercial name Silica Gel 60N, granular, neutral, 0.040 mm-0.100 mm; n-heptane:ethyl acetate=30:1) to obtain the title compound (18.5 mg) as colorless oil.
400 MHz 1H-NMR (CD3OD) δ (ppm) 0.64-0.76 (m, 12H), 0.88 (t, J=7.6 Hz, 3H), 0.94 (d, J=7.6 Hz, 3H), 0.99 (t, J=7.6 Hz, 9H), 1.00 (t, J=7.6 Hz, 9H), 1.28-1.39 (m, 1H), 1.42 (s, 3H), 1.52-1.63 (m, 2H), 1.81-1.94 (m, 2H), 2.70 (dd, J=2.2, 8.0 Hz, 1H), 2.92 (dt, J=2.2, 8.0 Hz, 1H), 3.80 (dt, J=3.2, 6.0 Hz, 1H), 9.61 (s, 1H).
Reference Example 7




Synthesis of 5,6-anhydro-1,2,4,7-tetradeoxy-4-methyl-8-C-methyl-3,8-bis-O-triethylsilyl)-L-glycero-D-galacto-nonitol (R9), (1R)-1,2-anhydro-3,5-dideoxy-4-C-[(1E)-3-hydroxyprop-1-en-1-yl]-1-{(1S,2S)-1-methyl-2-[(triethylsilyl)oxy]butyl}-4-O-(triethylsilyl)-D-erythro-pentitol (R10), (2S,3S,4E,6S,7R,10R)-7-hydroxy-2-[(1E)-3-hydroxy-1-methylprop-1-en-1-yl]-3,7-dimethyl-12-oxo-10-[(triethysilyl)oxy]oxacyclododec-4-en-6-yl acetate (R11) and (2S,3S,4E,6S,7R,10R)-7-hydroxy-2-[(hydroxyethyl)-3,7-dimethyl-12-oxo-10-[(triethylsilyl)oxy]oxacyclododec-4-en-6-yl acetate (R12)
3,16,21-tris-[(triethylsilyl)oxy]-pladienolide D (21 mg, 0.235 mmol) was dissolved in a mixture solvent of dichloromethane (25 ml) and methanol (25 ml). This reaction solution was cooled to −78° C. and Ozone (flow rate 2 l/min, voltage 90 V) was blown into the reaction solution for 3 minutes during stirring. After adding sodium borohydride (88.9 mg, 2.35 mmol), the reaction solution was warmed to 0° C. and stirred for 1.5 hours. The reaction solution was diluted by ethyl acetate and washed with brine. The organic layer was dried over anhydrous sodium sulfate, the drying agent was filtered off and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (Merck, commercial name Silica Gel 60, 230-400 mesh; hexane: ethyl acetate=10:1→3:2→1:2). The title compound R9 (77.3 mg) was obtained as colorless oil. The title compound R10 (17.3 mg) was obtained as colorless oil. The title compound R11 (38.5 mg) was obtained as colorless oil. The title compound R12 (49.1 mg) was obtained as colorless oil.
R9: 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.64-0.76 (m, 12H), 0.89 (t, J=7.2 Hz, 3H), 0.98 (d, J=7.6 Hz, 3H), 0.95 (t, J=8.0 Hz, 9H), 1.00 (t, J=8.0 Hz, 9H), 1.26 (s, 3H), 1.28-1.40 (m, 1H), 1.52-1.65 (m, 2H), 1.68 (dd, J=6.4, 14.4 Hz, 1H), 1.77 (dd, J=5.2, 14.4 Hz, 1H), 2.71 (dd, J=2.4, 8.0 Hz, 1H), 2.95-3.02 (m, 1H), 3.48 (d, J=9.6 Hz, 1H), 3.55 (d, J=9.6 Hz, 1H), 3.79 (dt, J=3.2, 6.4 Hz, 1H),; LRMS C23H50NaO4Si2 (M+Na+) Calcd: 469.31, Found: 469.16
R10:400 MHz 1H-NMR (CD3OD) δ (ppm) 0.69 (q, J=8.0 Hz, 6H), 0.70 (q, J=8.0 Hz, 6H), 0.89 (t, J=7.6 Hz, 3H), 0.96 (d, J=7.2 Hz, 3H), 1.02 (t, J=8.0 Hz, 9H), 1.03 (t, J=8.0 Hz, 9H), 1.28-1.40 (m, 1H), 1.46 (s, 3H), 1.52-1.66 (m, 1H), 1.70-1.84 (m, 1H), 2.69 (dd, J=2.4, 8.4 Hz, 1H), 2.95 (dt, J=2.4, 5.6 Hz, 1H), 3.81 (dt, J=3.2, 6.4 Hz, 1H), 4.12 (d, J=4.0 Hz, 2H), 5.78-5.88 (m, 2H),; LRMS C25H52NaO4Si2 (M+Na+) Calcd: 495.33, Found: 495.31.
R11: LRMS C25H44NaO7Si (M+Na+) Calcd: 507.28, Found: 507.27.
R12: 400 MHz 1H-NMR (CD3OD) δ (ppm) 0.66 (q, J=8.0 Hz, 6H), 1.02 (t, J=8.0 Hz, 9H), 1.11 (d, J=6.8 Hz, 3H), 1.16 (d, J=6.4 Hz, 3H), 1.24 (s, 3H), 1.34-1.72 (m, 4H), 2.13 (s, 3H), 2.45-2.68 (m, 2H), 2.73-2.85 (m, 1H), 3.85-3.95 (m, 1H), 3.98-4.12 (m, 1H), 4.77 (d, J=10.4 Hz, 1H), 5.13 (d, J=9.2 Hz, 1H), 5.64-5.80 (m, 2H); LRMS C23H42NaO7Si (M+Na+) Calcd: 481.26, Found: 481.22.

## Claims

1. A process for producing a compound represented by Formula (6):



wherein P2, P3 and R2 are the same as defined below, characterized by comprising reacting a compound represented by Formula (7):




wherein P3 means a protecting group for hydroxy group; and Het means a 1-phenyl-1H-tetrazol-5-yl group, with a compound represented by Formula (8):




wherein P2 means a protecting group for hydroxy group; and R2 means a phenyl group which may be substituted, in the presence of a base.

2. The production process according to claim 1, wherein the base is potassium bis(trimethylsilyl)amide.