PROCESS FOR PREPARING 4-HYDROXYCYCLOPENT-2-EN-1-ONE

Abstract: Methods for preparing 4-hydroxycyclopent-2-enones and more specifically to methods for preparing optically active 4-hydroxycyclopent-2-en-1-one and 4-hydroxycyclopentan-1-one. The compounds have ready application in the synthesis of prostaglandins.

Description: Description Process for Preparing 4-Hydroxycyclcpent-2-En-l-One Field of the Invention The present invention relates to processes for preparing 4-hydroxycyclqpent-2-enones. Background Art 4(R)-Hydro ycyclopent-2-en-l-one (1) and 4(S)-hydroxy- cyclopent-2-en-l-one (2) characterized by the structural formulae shown below, and the racemate of these enantiαners are important inteπnediates in the synthesis of prostaglandins and other natural products. One of the shortest and simplest routes for preparing prostaglandins involves the 1,4-addition of the β-chain to 4-alkoxycyclopent-2-en-l-one and the trapping of the resulting enolate with the -chain [T. Tanaka et al. Tetrahedron, 33, 1105 (1977) . For the conversion of the racemate (1 + 2) into racanic prostanoids, see G. Stork and . Isobe, J. Am. Chan. Soc., 97, 6260 (1975) ; M. J. Loots and J. Schwartz, Tetrahedron Lett., 4381 (1978) ; J. W. Patterson and J. H. Fried, U.S. Pat. 3,847,962 (1974); U.S. Pat. 3,872,139 (1975) ] . In the conjugate addition, the£-chain approaches trans to the C-ll alkoxy group and the substituent trapping of the enolate gives the desired (all trans orientation) absolute configuration as in natural prostaglandins. This is now ccnomonly known as the three component coupling process [R. Noyori and M. Suzuki, Angew Chemie, Int. Ed., 23, 847 (1984)]. The enanticmeric 4(S)-hydroxycyclσpent-2-en-l-one (2) is a key chiral intermediate in the synthesis of Maytansine [M. Samson et al. Tetrahedron Lett., 3195 (1977)]. The usefulness of these chirons, _1 and 2, is further discussed by M. Harre et al [Angew Chemie Int. Ed., 21, 480 (1982)]. 4(R)-Hydroxycyclo- pent-2-en-l-one {1) has been prepared previously in 85% optical purity by synthesis from the (2S,3S)- or (-)- enanticmer of tartaric acid [K. Ogura et al. Tetrahedron Lett., 759 (1976)], and in up to 90% enanticmeric excess, but low overall yield, from cαnbined microbiological (hydrolysis) and chanical transformation of 3,5-diacetoxycyclopent-l-ene [T. Tanaka et al. Tetrahedron, 32, 1713 (1976)]. The same (R)-enanticmer (1) has also been prepared by chemical modification of the fungal metabolite terrein [L. A. itscher et al. Tetrahedron Lett., 2553 (1978)]. The opposite 4(S_)- hydroxyclopent-2-enone (2) has been prepared in 86% optical purity from (2R,3R)- or (+)-tartaric acid [K. Ogura et al, (1976) ] and in low enanticmeric excess and overall yield from 3,5-diacetoxycyclopent-l-ene [T. Tanaka et al,' Tetrahedron, 32, 1713 (1976) ] . In addition, optically pure enanticmsrs of 1 ^ and 2_ have been prepared from phenol via a long reaction sequence and chanical resolution M. Gill and R. W. Richards, Tetrahedron Lett., 1539 (1979)]. Each of the aforementioned methods is geneally unsuitable for industrial application because of cost, use of corrosive reagents, etc. Disclosure of Invention The present invention provides improved processes for producing racemic and optically-active 4-hydroxycyclopent-2- enones from readily available, moderate cost, raw materials such as cis and trans-3,5-dihydroxycyclcpent-l-ene. More specifically, it provides processes for the stereo- selective oxidation of 3,5-dihydroxycyclcpent-l-ene by the action of microbial enzymes. The meso diol, cιs-3,5-d:iIιydroxycyclopent-l-ene (3_) can be prepared via a 1,4-σycloaddition ot cyclqpentadiene with singlet oxygen [C. Kaneko et al. Synthesis, 876 (1974) ; C. S. Foote and S. exler, J. Am. Chart. Soc., j36_, 3879 (1964)]. Mixtures of trans and cis-3,5-dihydroxycyclopent-l-ene can be synthesized frc cis-3,5-dibrcmocyclopent-l-ene [L. N. Oven and P. N. Smith, J. Chem. Soc. , 4035 (1952)] . Because the meso-diol, 3_, is a solid (m.p.59-60°C) whereas the racanic trans mixture (4R+4S) is a liquid at room taπperature, the meso-diol can be crystallized to yield a semi-solid consisting of approximately three parts of [ and one part of the trans- enanticmers 4R+4S) . Conversely, the mother liquor remaining consists of approximately one part of 3_ and three parts of 4R + 4S. The microbial process of the present invention has a distinct advantage over chemical oxidative methods. It avoids the need of protection-deprotection and the use of expensive oxidative reagents [T. Tanaka et al. Tetrahedron, 32, 1713 (1976) ] . Furthermore, such stereochanical differentiation by microbial enzymes is exceedingly difficult to achieve chemically. Theoretical Considerations for Preparing JL and 2 ^ The following theoretical considerations are provided as a means for facilitating an understanding of the stereo- selectivity of microbial oxidations, and there is no intention to be bound by the concepts presented. In considering the oxidation of the meso-diol, 3_, one may envisage the following possibilities: When the microorganism contains a single oxido-reductase that is enantioselective, oxidation of the S_-alcohol of 3_ affords 1_ only (path A) , whereas oxidation of the R-alcohol of 3_ affords 2_ only; alternatively, if the microorganism oxidizes both R- and S-alcohols, the resulting 4-hydroxycyclopent-2-en-l-one would be only partially enantioselective or racanic. Further complications may ensue if the microorganism possesses reductases that catalyze the reduction of the double bond (path 3) to yield 5R and/or 5£5 as shown below. To prepare the desired prostaglandin synthon, _1., it is imperative to find a microorganism that catalyzes only path A (enantioselective for S-alcohol) . A similar analysis may be made for the microbial oxidation of the trans-diols, 4R and 4S. Stereospecific oxidation of S_-carbinol affords 2_, and of R-carbinol affords _1 as depicted below. In this case, an enzyme system that is enantioselective for the R-alcohol is required to prepare 1_. Microorganisns which have the desired oxidative activity are well known in the microbiological art and any of such microorganisms can be employed in conducting the process of the present invention [see K. Kieslich, "Microbial Transformations of Non-Steroid Cyclic Compounds" (Georg Thieme Publishers, Stuttgart, 1976)], with any of the genera of microorganisms specifically set forth herein being particularly suitable. The 3,5-dihydroxycyclopent-l-ene can be incorporated in a nutrient medium of standard composition in which such organisms are cultivated and the usual conditions of fermentation which are well kncwn in the art can then be employed to effect the oxidative transformation. Alternative¬ ly, the active principle can be removed from the growing culture of the microorganisms, for example, by lysis of the cells to release the enzymes, or by suspension of the resting cells in a fresh aqueous medium. Moreover, the cells and the enzyme can be immobilized in accordance with well kncwn procedures to further reduce the cost of the process. In any of these techniques, an alcoholic function will be selectively oxidized as long as the active enzyme elaborated by the microorganism is present. Of course, the temperature, time and pressure conditions under which the contact of the cyclopentenediol with the oxidative enzyme is carried out are interdependent as will be understood and readily apparent to those skilled in the art. For example, with gentle heating and at atmospheric pressure, the time required will be less than if the reaction progresses at room temperature under conditions otherwise the same. Neither temperature, nor pressure, nor time should be permitted to exceed limits that will result in the substrate being degraded. Where a growing culture of the organism is being used, the process conditions should also be sufficiently gentle so the organism is not killed before it elaborates sufficient proteolytic enzymes to permit destruction of the oxidative enzyme. Generally, at atmospheric pressure, the reaction can be carried out at a temperature in the range frc about 10° to about 35°C, for from about 12 hours to about 10 days. In general, microorganisms of the orders Moniliales, Endαnycetales, Eubacteriales and Eurotiales have been found to be particularly suitable in the method of this invention. It has been observed, however, that there are variations in the efficiency with which different orders, genera, and species of microorganisms accomplish the oxidative process of this ivnention. Also, relative efficiency of a given organism to accomplish such oxidation and the relative proportion of 4- hydroxycyclσpent-2-en-l-one a d 4-hydroxycyclσpentan-l-one formed can be severaly affected by the ccmposition of the fermentation medium. It will be obvious to those skilled in the art that by cloning and sub-cloning the gene of the desired oxidative enzyme one can eliminate the interfering reductase and enhance the production of the desired oxidase in the transformed organism. Suitable organisms for accomplish¬ ing the desired oxidative process can be readily ascertained frcm the screening procedure which is outlined belcw. General Screening Procedure A variety of microorganisms were examined for their abilities to oxidize 3,5-dihydroxycyclopent-l-ene into 4-hydroxycyclcpent-2-en-l-one and 4-hydroxycyclcpentan-l-one. OH 0 0 The microorganisms were maintained on agar slants of the following composition: a) Bacteria Gms Agar 20 Bacto-beef extract 3 Bacto-peptone .5 Distilled water, q.s. 1 liter (Sterilized 15 min at 20 p.s.i.) b) Fungi Gms Malt extract 20 Glucose 20 Peptone 1 Agar 20 Distilled water, q.s. 1 liter (Sterilized 15 min at 20 p.s.i.) c) Yeasts Gms Agar 20 Glucose 10 Yeast extract 2.5 K 2 HP0 4 1 Distilled water, q.s. 1 liter (Sterilized 15 min at 20 p.s.i.) Surface growth from a one-^week old agar slant of a microorganism was suspended in 5 ml of an 0.85% saline solution. An aliquot (o.5 ml) of this suspension was used to inoculate a 50 ml Erleπmeyer- flask containing 10 ml of one of the following fermentation media: Medium A Gms Difco nutrient broth 8 Yeast extract 1 Glycerol 5 Sodium citrate 5 Distilled water 1 liter pH adjusted to 7.0 (autoclaved at 20 psi for 15 minutes) Medium B Gms Glucose 15 Yeast extract 5 Malt extract 20 Bacto-peptone 10 Distilled water, q.s. 1 liter pH 6.5 (Sterilized for 15 min <at 20 p.s.i.) Medium C (Soy-Dextrose) Gms Soybean meal 4 Dextrose 20 NaCl 5 K 2 HK> 4 5 Yeast 5 Distilled water 1 liter pH adjusted to 7.0 (autoclave at 15 psi for 15 minutes) The flask was incubated at 25°C on a rotary shaker (250 cycles/min - 2" radius) for 24-48 hours until visible good growth was observed. 3,5-Dihydroxycyclopent-l-ene (10 mg of cis + trans iscmers dissolved in 0.02 ml of ethanol) was added and the flask was incubated under the same conditions for another 24 hours. An. aliquot (2 ml) was then removed for analysis. Analysis The 2 ml aliquot of the fermentation broth was extracted with ethyl acetate (2 ml, twice) . The combined organic layer, dried over sodium sulfate, was evaporated to dryness. The residue was dissolved in acetone and analyzed by thin-layer chrcmatography (TIC) using Brinkman (EM) plates (0.25 mm thickness) of silica gel containing PF-254 indicator. The plates were developed in a solvent system consiting of CH Cl - acetone (6:4) and the relative mobilities were: 4-hydroxy- cyclcpentan-1-one and 4-hydroxycyclopent-2-en-l-one (R f = 0.43); 3,5-dihydrαxycyclopent-l-ene (R f = 0.18), as revealed by spraying the TDC plate with a reagent consisting of: 50 ml of concentrated acetic acid: 1 ml of concentrated E ΞO . ; and 2 4' 0.6 ml of 4-methoxybenzaldehyde. Upon gentle heating of the TDC plate, 4-hydroxycyclopentan-l-one emerges as a yellcw spot whereas 4-hydroxycyclcpent-2-en-l-one emerges as a brownish or purple spot depending on the concentration and extent of heating of the TIC plate. EXAMPLES 1-50 The following microorganisms were found to possess the desired oxidative ability using the aforementioned procedure: Fermentation Medium A 1. Escherichia coli ATCC 10536 2. Mycobacterium sp. NEL 3805 3. Mycobacterium sp. NRR 3683 4. Mycobacterium fortuitum NRRL 8119 5. Mycobacterium sp. NRRL 15051 6. ^cobacterium phlei NRRL 8184 7. Mycobacterium phlei NRRL B15050 8. Mycobacterium smegmatic ATCC 607 9. Mycobacterium smegmatis ATCC el4468 10. Bacillus megateriu ATCC 9885 11. Bacillus subtillis ATCC 6633 12. Erwinia carotovora subsp. carotovora ATCC 21917 13. Arthrobacter sp. ATCC 19140 14. Arthrobacter sp. ATCC 21237 15. Bacillus cereus ATCC 13824 16. Nocardia corallina ATCC 19148 17. Pseudomonas aeruginosa ATCC 15442 18. Pseudαnonas stutzeri ATCC 11607 Fermentation Medium B 19. Rhodococcus sp. ATCC 17037 20. Nocardia restricta ATCC 14887 21. Hansenula saturnus NRRL 1304 22. Hansenula ancmala ATCC 20144 23. Pseudcmonas putida ATCC 12633 24. Pseudcmonas putida ATCC 17428 25. Rhodococcus sp. ATCC 19070 26. Candida lipolytica NRRL Y-1095 27. Candida lipolytica NRRL 925A 28. Pichia alcoholophilia NRRL 114 29. Torula lactosa NRRL Y-329 30. Oidium lactis NRRL Y-552 31. Saccharαπoyces ellipsoides NRRL Y-12,632 32. Candida quilliermondii ATCC 9058 33. Saccharcmyces cerevisiae NRRL Y-214a 34. Saccharcmyces fermenti NRRL Y-1018 Fermentation Medium C 35. Aspergillus amstelodami ATCC 16464 36. Aspergillus fumigatus ATCC 10894 37. Aspergillus niger mut. cinnamcmeas ATCC 1027 38. Aspergillus niveo-glaucas ATCC 10075 39. Aspergillus ruber ATCC 16441 40. Fusarium oxysporium f. sp. conglutinans ATCC 9990 41. Fusarium moniliforme ATCC 10052 42. Fusariuim solani ATCC 11712 43. Fusarium heterosporum ATCC 15625 44. Penicillium vinaceum ATCC 10514 45. Penicillium notatum ATCC 8478 46. Byssochlamys fulva ATCC 10099 47. Aspergillus terreus ATCC 10020 48. Helminthosporium dematioideum ATCC 24346 49. Metarrhizium aniscpliae ATCC 24942 50. Sporobolomyces sp. NRRL 1584 NRRL - Northern Regional Research Laboratory, Peoria, Illinois ATCC - American Type Culture Collection, 12301 Parklawn Drive, Rockville, Maryland 20852 To further confirm the chemical identity, the optical purity and the absolute configuration of 4-hydroxycyclcpent-2- en-l-one, the following general preparative procedure was used. ' EXAMPLE 51 a) Incubation Conditions Rhodococcus sp ATCC 19070 was grown for 48 hrs in medium B and the cells were collected by centrifugation. -4 Phenazine methosulface (5 x 10 M) was added to 2 g of wet cell paste, suspended in 20 ml of 50 mM potassium phosphate buffer, pH 7.5. After incubation on a rotary shaker for 5 minutes at 25°C, 20 mg of cis-3,5-dihydroxycyclopent-l-ene (3) , dissolved in 50 ul of acetone, was then added to the resting cell suspension. After the reaction mixture was incubated on a rotary shaker (250 rpn, 2" radius) for 48 hrs at 25°C, the reaction was terminated by exhaustively extracting the mixture with equal volumes of ethyl acetate (three times) . The combined organic layer was dried over NA 2 SO. and evaporated to dryness in vacuo. The residue was dissolved in a small volume of the mobile phase and applied to a column (0.6 x 16 cm) of silica gel (2 g) . The column was eluted with hexane-ethyl acetate (2:1) and 2.5 ml fractions were collected. Fractions 11-20 were pooled and evaporated to dryness in vacuo to yield 9 mg of 4R-hydroxycyclopent-2-en-l- one (JL) as an oil; hi n.m.r. (CDC1 3 ) 52.25 (1H, dd, J = 18 and 3 Hz, H-C_) , 2.80 (1H, dd, J = 18.5 and 6 Hz, H-C c ) , 3.5 (1H, bs, OH), 4.98 (1H, m, H-C j ) , 6.20 (1H, dd, J = 6 and 1 Hz, H-C 2 ), 7.60 (1H, dd, J = 6 and 2 Hz, H-C ; IR (neat): 3375, 1715 and 1587 cm "1 ; MS (70 eV) ; 98 (M+) . This compound (R-l) exhibited a positive cotton effect at 215 nm and a negative one at 317 nm. b) Determination of Optical Purity Because of the small sample size, the optical purity of JL is more accurately analyzed by converting 1_ (3 mg) into its MTPA ester by reacting with (+)- -methoxy-c< -(trifluorcmethyl)phenylacetyl chloride (MTPA-Cl) in pyridine [J. A. Dale et al, J. Org. Chan., 34, 2543 (1969)]. The resulting MTPA esters were analyzed by HPLC on an Alltech uporasil (10 micron) column (4.5 mm ID x 50 cm) . The column was eluted with CHCl_-diethyl ether-hexane (1:4:16) at a flow rate of 1.5 ml per min and the absorbance at 254 nm was monitored. The retention times were: JL(R) : 22 min and _2(S) : 19 min. The enanticmeric excess (ee) was calculated by quantitatively measuring the peak areas of diasterecmers. The sample of JL, derived from Rhodococcus sp. ATCC 19070, was established to have an ee of 0.70. EXAMPLES 52-57 Using the same procedures as example 51 with the growth media and conditions specified below, the following microorganisms transformed cis-3,5-dihydroxycyclopent-l-ene (3_) into either 4R-hydroxycyclopent-2-en-l-one (1) or 4&-hydroxycyclopent-2-en-l-one (2_) of varying optical purity. Stereo Enanticmeric Growth chemistry excess Microorganisms medium/time of product (ee) Mycobacterium sp. A/72 hrs S 0.52 NRRL 3805 Mycobacterium A/72 hrs R 0.53 fortuitum * NRRL 8119 Mycobacterium phlei A/72 hrs R 0.47 NRRL B15050 Mycobacterium sp. A/72 hrs S 0.73 NRRL 15051 Nocardia restricta B/48 hrs R 0.07 ATCC 14887 Hansenula saturnus B/48 hrs R 0.57 EXAMPLE 58 The procedure of example 51 was repeated using Rhodococcus sp. ATCC 19070 except that phenazine methosulfate was omitted frcm the incubation mixture to give 4S-hydroxycyclqpentan-l-one (5S) in high yield. EXAMPLE 59 The procedure of example 51 was repeated using Mycobacterium sp. NRRL 15051 in absence of phenazine methosulfate to give 4R.-hyάroxycyclopentan-l-one (5R) in high yield. EXAMPLE 60 The procedure of example 51 was repeated using Mycobacterium sp. NRRL 15051 except that (+)trans-cyclσpent- 2-ene-l,4-diol 4R + ^S) was used as the substrate to give 4R-hydroxycyclcpent-2-en-l-one (1) in good yield. EXAMPLE 61 The procedure of example 51 was repeated except that 1,4-naphthoquinone was substituted for phenazine methosulfate to give 4R-hydroxycyclopent-2-en-l-one (1) in high yield. . EXAMPLE 62 The procedure of example 51 was repeated except that menadione was substituted for phenazine methosulfate. 4R- hydroxycyclopent-2-en-l-one (1) was recovered in high yield. EXAMPLE 63 The procedure of example 51 was repeated except that 1,2- naphthoquinone was substituted for phenazine methosulfate. 4R-hydroxycyclopent-2-en-l-one (JL) was recovered in high yield. EXAMPLE 64 The procedure of example 51 was repeated except that potassium ferricyanide was substituted for phenazine methosulfate. 4R-hydroxycyclopent-2-en-l-one (1) was recovered in high yield. EXAMPLE 65 The procedure of example 51 was repeated except that tetramethylphenylenediamine was substituted for phenazine methosulfate. 4R-hydroxycyclopent-2-en-l-one (JL) was recovered in high yield. Phenotype characteristics and the taxonomy of the various orders and species of microorganisms set forth in the foregoing Examples and in the claims can be readily found by reference to Bergey's Manual of Systematic Bacteriology, Vol. 1, Williams and Wilkins, 428 E. Preston Street, Baltimore, MD 21202 and in The Prokaryotes, Edited by Mortimer P. Starr, Heinz Stolp, Hans G. Truper, Albert Balows and Hans G. Schlegel, (Springer-Verlag, Berlin, Heidelberg, New York) . It will also be understood by those skilled in the microbiological arts that microorganisms of the Orders and Species specified can be genetically engineered or mutated by well known methods to increase their capability for preferentially expressing enzymes which will enhance the production of the desired 4-hydroxycyclopent-2-enones or to mir mize or eliminate the expression of enzymes which would interfere with the desired reactivity.

Claims: Claims 1. A method for preparing 4-hydroxycyclqpent-2-enones which comprises subjecting 3,5-dihydroxycyclopent-l-ene to the oxidative enzymatic action of a microorganism selected from the group consisting of the orders Endαπycetales, Eubacteriales, Eurotioles and Monilialas and recovering the desired 4-hydroxycyclopent-2-enone frcm the reaction mixture. 2. A method according to claim 1 wherein the 4-hydroxy- cyclopent-2-enones recovered are 4-hydroxycyclopent-2- en-l-one and 4-hydroxycyclcpentan-l-one. 3. A method according to claim 2 wherein the 4-hydroxy- cyclopent-2-enones recovered are optically active. 4. A method according to claim 1 wherein the reaction is effected with immobilized cells of the microorganisms. 5. A method according to claim 1 wherein the reaction is effected with isolated enzyme elaborated by the microorganism. 6. A method according to claim 5 wherein the enzyme has been irrmobilized. 7. A method according to claim 1 wherein the reaction is effected by a genetically engineered organism. 8. A method according to claim 1 wherein the reaction is carried out in the presence of a compound selected from the group consisting of phenazine methosulfate,1,4- naphthoquinone, potassium ferricyanide, 1,2-naphtho- quinone and tetra methylphenylenediamines whereby the accumulation of optically active 4-hydroxycyclopent-2- ene-1-one in the reaction mixture is promoted. 9. A method according to claim 1 wherein the microorganism is Rhodococcus sp. ATCC 19070. 10. A method according to claim 1 wherein the microorganism is Mycobacterium sp. NRRL 15051. 11. A method according to claim 1 wherein the microorganism is Hansenula saturnus NRRL 1304. 12. A method according to claim 1 wherein the microorganism is Mycobacterium phlei NRRL B15050. 13. A method according to claim 1 wherein the microorganism is Mycobacterium fortuitum.

Inventors: SIH CHARLES J, SIH, CHARLES, J.
Applicants: WISCONSIN ALUMNI RES FOUND, WISCONSIN ALUMNI RESEARCH FOUNDATION
Application year: 1986
Main classification: C12P7
IPC codes: C12P7