bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature and pH dependence of proton N.M.R. of glutamine in peptides
Authors: Zanacchi RM , Moore WJ
Published: September 2010

The proton n.m.r. spectra
of the peptides Ala-Glu-Gly-Gln-Gly and Gly- Gln-Gly as measured in
dimethyl sulfoxide over a range of temperatures yielded kinetic parameters for
rotation about the carbon-nitrogen bonds of the glutamine side chains of
ΔH‡ 71.6 kJ mol-1, ΔS‡ 2.1 J mol-1
K-1, and ΔH‡/70.6 kJ mol-1, ΔS‡
-0.5 J mol-1 K-1, respectively, at 298 K. On pH titration
in dimethyl sulfoxide/water solutions, the chemical shifts of the cis protons
of the glutamine amide remained constant whereas those of the trans protons
were altered with a pK corresponding to that of the
terminal glycine.
Micellar catalysis of the basic hydrolysis of anilides. III. α-Substituted N-methyl-N-p-nitrophenylacetamides
Authors: Broxton TJ , Duddy NW
Published: September 2010

The basic hydrolysis of a
number of α-substituted N-methyl-N-p- nitrophenylacetamides has been
studied both in the presence and absence of micelles of cetyltrimethylammonium
bromide (ctab). Unlike the related p-nitrophenyl
esters of a-substituted acetic acids, no evidence for the operation of the E1cb mechanism in the basic hydrolysis has been detected.
Reasons for the differences between the amides and esters are discussed.
Substituent effects on the hydrolysis of the amides have been studied both by
single-parameter and dual-parameter analysis.
The synthesis and stereochemistry of odorine
Authors: Babidge PJ , Massy-Westropp RA , Pyne SG , Shiengthong D , Ungphakorn A , Veerachat G
Published: September 2010

The stereochemistry of
naturally occurring odorine has been established as (+)-(E,2S,2?R)-2-methyl-N-[1'-(1''-oxo-3''-phenylprop-2'-
enyl)pyrrolidin-2'-yl]butanamide by synthesis of
(-)-odorine and (+)- dihydroodorine from L-proline.
Excess enthalpies and excess volumes for n-hexane + 2-methylpentane, + 3-methylpentane and + 2,3-dimethylbutane at 283.15, 298.15 and 313.15 K
Authors: Ott JB , Grigg RB , Goates JR
Published: September 2010

Excess enthalpies and
excess volumes were determined over the entire composition range and at the
three temperatures 283.15,298.15 and 313.15 K for mixtures of n-hexane with the
three isomeric hexanes: 2- methylpentane, 3-methylpentane and 2,3-dimethylbutane.
The excess enthalpies were measured with a microflow calorimeter and the excess
volumes with a vibrating-tube densimeter. ��� The results are correlated with the
molecular shape of the isomeric hexane.
Phase behaviour of mixtures of dipolar hard spheres: mean spherical approximation
Authors: Isbister D , Freasier BC , Bearman RJ
Published: September 2010

The role of intermolecular
forces in the phase behaviour of mixtures of dipolar hard spheres is
investigated by using the mean spherical approximation of statistical
mechanics. This approach yields an analytical expression for the dipolar
contribution to the internal energy which is numerically integrated to obtain
the Helmholtz free energy. These results are then used to obtain the dipolar
contribution to the 'energy pressure' and the Gibbs free energy. The double
tangent construction gives details of the composition of fluid phases in
equilibrium. The composition-temperature curves exhibit liquid-liquid and
liquid-fluid immiscibilities for three selected molecular systems in which only
the diameter of one species varies, while the rest of the potential parameters
are held constant.
One-dimensional analysis of the theory of dense fluids
Authors: Haymet ADJ , Nordholm S
Published: September 2010

A simple reduction of
realistic three-dimensional model systems to an approximately equivalent
one-dimensional form is proposed. This reduction is then applied to the
standard Lennard-Jones model of the simple fluid and
isotherms are obtained from three approximate theories. The first two
correspond to the Barker-Henderson and Andersen-Chandler-Weeks repulsive
reference system perturbation theories and the third is a perturbation theory
based on the exactly solvable nearest neighbour model. Comparison of the three
theories in the liquid region is used as a preliminary investigation into the
importance of correlations due to attractive forces. The same reduction is then
used in the development of a new isobaric cell theory. This theory eliminates
some of the major sources of error in traditional cell theories. Comparison
with experimental isotherms for argon shows good agreement. The new theory does
not predict condensation but, through a mechanism of Landau phase mixing,
reproduces the flat parts of the isotherms to a good approximation.
Some applications of competitive coupling in peptide synthesis
Authors: Stewart FHC
Published: September 2010

A variant of the
conventional Goodman-Stueben procedure involving
generation of two competing activated carboxyl groups in the same coupling
component has been used for the synthesis of a number of α,γ-
L-glutamyl branched peptides. Application of a similar competitive situation
has also been demonstrated in the 3-nitro-L-tyrosine series.
Vapour pressures and excess Gibbs free energies of cyclohexane + n-hexane, + n-heptane and + n-octane at 298. 150 K
Authors: Martin ML , Youings JC
Published: September 2010

By means of a continuous
dilution vapour pressure apparatus the excess Gibbs free energies of binary
liquid mixtures of cyclohexane with n- hexane, n-heptane and n-octane at 298.150
K have been determined. The values of this excess function were positive at all
concentrations and decreased with an increase in the chain length of the
n-alkane. The maximum values, 75.9, 49.7 and 24.6 J mol-1, for the
respective systems occurred in mixtures with a mole fraction of cyclohexane
greater than 0.5.
Generalized van der Waals theory. III. The prediction of hard sphere structure
Authors: Nordholm S , Johnson M , Freasier BC
Published: September 2010

This article is devoted to
further development of the generalized van der Waals theory and its application
to non-uniform hard sphere fluids. A coarse-graining assumption included in the
original derivation is replaced by a weaker assumption recognizing the non-zero
range of hard core interactions. The new fine-grained theory thus contains a
non-local entropy functional and allows fluid structure on a length scale
shorter than the hard core diameter to be resolved. Moreover, it contains a
simplified representation of the mechanism leading to hard sphere structure due
essentially to geometrical packing constraints. This is shown by application of
the theory to hard sphere adsorption profiles in the case of a hard wall and to
radial distribution functions of a hard sphere fluid. The amount of structure
is underestimated partly due to the use of a density-independent excluded
volume. It is shown that this flaw can be remedied by use of a hard- sphere entropy
functional which successfully interpolates between the original high density
estimate and the known behaviour in the low density limit.
Studies in the tricyclooctane series. IV. A new and convenient synthesis of 3,3-Dihalo-cis-transoid-cis-tricyclo[5,1,0,02,4]oct-5-enes
Authors: Banwell MG , Halton B
Published: September 2010

A simple and efficient
synthesis of 3,3-dibromo- and 3,3-dichloro-cis- transoid-cis-tricyclo[5,1,0,02,4]-oct-5-ene
(3a,b) (gem-dihalo-anti- bishomobenzenes) has been
developed from bicyclo[4,1,0]hept-3-ene (9).
Ab initio studies on amides: conformational preferences of diacetamide and barriers to interconversion of the conformers
Authors: Radom L , Riggs NV
Published: September 2010

Diacetamide, like other
diacylamines, is capable of existing in three basic conformations about the N-C
bonds. Optimization (STO-3G) of model systems in which all first-row atoms and
the amido hydrogen atom are held coplanar predicts that the E,Z conformer (3)
is of lowest energy, the Z,Z conformer (2) of somewhat higher energy (4.2 kJ
mol-1), and the E,E conformer (1) of highest energy (23.6 kJ mol-1);
4-31G evaluation of the energies suggests that (1) and (2) are each of higher
energy than (3) by 27-28 kJ mol-1. It is suggested that (2) is
destabilized with respect to (3) by electrostatic repulsion of the two
negatively charged oxygen atoms whereas destabilization of (1) is due to
substantial methyl-methyl steric interactions as reflected in the very wide <CNC
(136°); the energy of (1) is, however, raised by out-of-plane or rotational
movements of the methyl groups, i.e., the preferred structure (excluding methyl
hydrogens) is planar. The calculated height of the barrier to internal rotation
of (3) by either of two model transition states is 41-45 kJ mol-1,
in good agreement with an experimental value of 45.2 kJ mol-1 in
solution at -60°.
The electric birefringences and conformations of some phenylsilanes
Authors: Armstrong RS , Aroney MJ , Higgs BS , Skamp KR
Published: September 2010

Electric dipole moments and
molar Kerr constants are reported for Ph3SiH, Ph3SiCl,
(Ph3Si)2O, Ph2SiH2, Ph2SiMe2
and Ph2SiCl2 as solutes in carbon tetrachloride or
cyclohexane solution at 298 K. The data are analysed in terms of the preferred
solution-state conformations.
Photolysis of some 1-substituted cycloocta-1,5-dienes: synthesis of 1-fluorotricyclo[3,3,0,02,6]octane
Authors: Cotsaris E , Della EW
Published: September 2010

A study of the photolytic
behaviour of several derivatives of cycloocta-1,5-diene as possible precursors
of bridgehead-substituted tricyclo[3,3,0,02,6]octanes is described.
Of the substrates examined, only 1-fluorocycloocta-1,5-diene successfully
underwent photocyclization giving 1-fluoro-tricyclo[3,3,0,02,6]octane.
1- Bromocycloocta-1,5-diene suffered fission of the carbon-bromine bond, while
cycloocta-1,5-diene-1-carbonitrile afforded a mixture of at least four
unsaturated isomers.
Electrolytic hydrogenation and hydrogenolysis of phenols at platinum black electrodes
Authors: Bagnell LJ , Jeffery EA
Published: September 2010

Electrochemical reduction
of phenols at platinum black electrodes in ethanolic hydrochloric acid, at
atmospheric pressure and room temperature, forms aromatic and aliphatic
hydrocarbons as well as ketones and alcohols. The products resemble those from
non-electrochemical hydrogenation.
The temperature dependence of the Kerr constant of polar liquids
Authors: Beevers MS , Khanarian G
Published: September 2010

The temperature dependences
of the Kerr constants of ten polar liquids in the range 275-343 K are reported.
They are H2O, D2O, MeOH, ButOH, CHCl3,
MeCN, PhCl, Me2SO, Me2CO and MeNO2. The Kerr
constants of all the liquids were found to have a T-1 and T-2 dependence, except
for ButOH which had an exp(-U/RT) dependence, where U is 28.0
kJ/mol. The Kerr effect, a sensitive probe of liquid structure, is related to
the polarization E and alignment<P2(cos
θ)>E where Pi(cosθ)(i = 1, 2) are the first
and second Legendre polynomials respectively, and θ is the angle between
the dipole axis of the reference molecule and the applied field. For the liquids
consisting of the axially symmetric molecules CHCl3 and MeCN, we
combine Kerr effect, dielectric and light scattering data to analyse the
temperature dependence of E, to
obtain information about two- and three-particle correlation functions. We also
present a qualitative discussion of the other liquids.
Reactions of remote functional groups in π-allyl palladium steroid complexes
Authors: Collins DJ , Jackson WR , Timms RN
Published: September 2010

Conditions are described
under which the oxidation and acetylation of hydroxyl groups can be carried out
in molecules containing remote π-allyl palladium groups. The reactions
were carried out in pyridine solution and the products were obtained as allylpyridine
complexes. The possibility of isomerism in these pyridine complexes is
discussed.
Binding of copper(II) ion to cytochrome c
Authors: Augustin MA , Yandell JK
Published: September 2010

Binding of aquacopper(11) ion to horse and tuna ferricytochrome
c has been investigated over the pH range 2-9. Between pH 4 and 7 the principal
binding site for horse cytochrome has an intrinsic
association constant of 1.8 × 104 1. mol-1 and pKa
of 6.5�0.6 at 25�C and ionic strength of 0.1. Binding to histidine
33 is consistent with this information, as well as with e.s.r.,
n.m.r. and visible absorption spectral data. Other sites also bind copper but
with association constants at least a factor of ten smaller. At high pH (>
8) further binding sites predominate.
Triazolopteridines. I. Simple s-Triazolo[4,3-c]pteridines and their derived [1,5-c] isomers
Authors: Brown DJ , Shinozuka K
Published: September 2010

The reaction of appropriate
pteridin-4-ylhydrazines (3) with orthoesters has been used to prepare
s-triazolo[4,3-c]pteridine (la) and some C-methylated
derivatives. Most of these underwent a Dimroth-like rearrangment
to yield the isomeric s-triazolo[1,5-c]pteridines
(2) but the 3-ethyl derivative(lc) gave an unusually stable intermediate,
N-[3-(5�-ethyl-1�,2�,4�-triazol-3�-yl)pyrazin-2-yl]- formamide (4a), which
resisted re-closure. In an attempt to prepare the parent rearranged heterocycle
(2a) independently, the last intermediate, N-acetoxy-N�-(pteridin-4-yl)formamidine
(6d), failed to cyclize: instead, it lost
acetic acid to give pteridin-4-ylcyanamide (6e). The main systems (1) and
(2)are easily distinguished by their characteristic n.m.r. spectra but not by
u.v. spectra.
The protonation of some Methylnaphthalen-1-ols in fluorosulfonic acid
Authors: Blackstock SM , Hartshorn MP , Richards KE
Published: September 2010

The protonations of
4-methyl-, 3,4-dimethyl- and 4,5-dimethyl-naphthalen-1-ols have been examined
for fluorosulfonic acid solutions at - 50�. The C2/C4 protonation ratios are
markedly dependent on the extent and position(s) of methyl substitution in the
naphthalen-1-ol system.
The behaviour of lead dioxide electrodes in acidic sulfate electrolytes
Authors: Matthews DB , Habib MA , Badwal SPS
Published: September 2010

The variation of discharge
capacity during charge-discharge cycling of a PbO2 electrode,
prepared by pressing PbO2 powder onto a smooth lead disc, in
sulfuric acid and acidic ammonium sulfate solutions of various concentrations
was investigated by the potentiodynamic technique. The discharge capacity was
found to increase with cycle number in 0.05-4.3 H2SO4; this was
explained in terms of the increase in porosity of the electrode with cycling.
The rate of increase was highest in a 1 mol dm-3 solution. The presence
of ammonium sulfate decreased the discharge capacity at all concentrations of sulfuric
acid except for the 1 mol dm-3
solution where it caused a small increase in capacity. The morphology of the
electrode was studied by scanning electron microscopy and the results are
correlated with the discharge capacity. These results indicated that a solution
of composition 0.5 mol dm-3 ammonium sulfate and 1.0 mol dm-3
sulfuric acid will produce a greater utilization of positive plate active material
(PbO2) during discharge. This result, taken together with the
results of earlier studies on lead in acidic sulfate electrolytes, points to
the possibility of a Pb/H2SO4,/PbO2 battery
for electric-vehicle propulsion.
Organomercury compounds. XXV. The mercuration of 1,2,4-trichlorobenzene
Authors: Deacon GB , Taylor BSF
Published: September 2010

Mercuration of boiling 1,2,4-trichlorobenzene with mercuric trifluoroacetate yields complex species, which were shown
to contain mainly �-(2,5,6-trichloro-1,3-phenylene)dimercury
bridging units and 2,3,6-trichlorophenylmercury terminal groups by halogenodemercuration reactions, and bis(2,3,6-tri-chlorophenyl)mercury, which was independently synthesized
from 2,3,6-trichlorophenyllithium and mercuric chloride. The organolithium compound was formed regiospecifically
on reaction of 1,2,4-tri-chlorobenzene with butyllithium. Mercuration of
1,2,4-trichlorobenzene with mercuric trifluoroacetate
(mole ratio 1 : 1) in trifluoroacetic acid results in regiospecific
monomercuration giving 2,4,5-trichlorophenylmercuric trifluoroacetate. This compound undergoes rearrangement in
boiling 1,2,4-trichlorobenzene to give a 2,3,6-trichlorophenylmercurial, and is
considered to be an intermediate in the mercuration
synthesis of bis(2,3,6-trichloropheny1)mercury. Thus, in 1,2,4-trichlorobenzene,
the kinetically and thermodynamically favoured mercuration
positions differ by contrast with the reported behaviour of
1,2,3-trichlorobenzene. Formation of the complex mercuration
products is considered to involve �-(2,5,6-trichloro-1,3-phenylene)bis(trifluoroacetato)dimercury and bis(2,3,6-trichlorophenyl)mercury
as intermediates. The new mercurials,
bis(2,3,5-trichloro-phenyl)-, bis(3,4,5-trichlorophenyl)- and
bis(2,4-dichlorophenyl)-mercury, have been prepared from the appropriate polychloroanilines by the diazonium
route.
The crystal structure of solvated Pt[CH3C(CH2PPh2)3][P(C6H4F)3]
Authors: Mason R , Williams GA
Published: September 2010

The molecular structure of the compound Pt(tripod)P(C6H4F)3½C4H8O where tripod = CH3C-
(CH2PPh2)3, has been determined by single-crystal X-ray diffraction methods at 295 K. Crystals
are triclinic, space group P1. Z 2, a 13.497(1), b 14.803(2), c 13.898(2) A, α 91.914(7), β 102.304(6),
γ 97.319(6)°. Diffractometry (Mo Kα) has provided significant [I ≥ 3σ(I)] Bragg intensities for
9528 independent reflections within 0 < (sin θ;)/λ ≤ 0.705 Ǻ-1.The structure has been refined by
least-squares methods to R 0.040. The coordination of the zero-valent platinum atom is distorted
tetrahedral with three Pt-P bonds, of lengths 2.292(1), 2.297(1), 2.303(1) Ǻ, to phosphorus atoms
of the tripod ligand, and a fourth Pt-P(C6H4F)3 bond of length 2.261(1) Ǻ. The P-Pt-P bond
angles involving the phosphorus atom of the monodentate ligand are large [118.23(5), 127.18(6),
122.20(5)°], whereas the steric constraints related to the tripod ligand are reflected in the other
P-Pt-P bond angles, none of which are very different from 90° [91.26(5), 99.56(5), 90.79(5)°]. We
suggest that the short Pt-P(C6H4F), bond is qualitatively explained by greater 's' electron character
in the metal σ orbital used in bonding with the monodentate ligand, and conversely more 'p' electron
character in the platinum σ orbitals used in bonding with the tripod ligand. We discuss the lack of
significant evidence for platinum to phosphorus π-bonding effects in the observed Pt-P bond lengths.
Nuclear magnetic resonance study of ligand exchange on hexakis(1,1,3,3-tetramethylurea)yttrium(III)
Authors: Pisaniello DL , Lincoln SF , Williams EH , Jones AJ
Published: September 2010

The first reported direct
study of monodentate ligand exchange on yttrium(III) shows the rate of
1,1,3,3-tetramethylurea exchange on [Y {O=C(NMe2)2}6]3+
to be independent of free ligand concentration consistent with the operation of
either a dissociative mechanism or an interchange mechanism where the encounter
complex stability constant is ≥ 300. Typical
data from this 270-MHz 1H n.m.r. study, where
rate of ligand
exchange = kex
6[Y {O=C(NMe2)2}63+]
are as
follows: kex(250
K) = 25�1 s-1, ΔH‡ = 27.1 � 0.5 kJ mol-1 and ΔS‡
= -108 � 2 J K-1 mol-1 for a CD3CN solution in
which [Y{O=C(NMe2)2}63+] and free
[O=C(NMe2)2] are 0.0039 and 0.028 mol dm-3
respectively. The preparations of [Y(ligand)6] (ClO4)3
where the ligand is O=C(NMe2)2, O=C(Me)(NHMe),
O=C(Me)(NMe2), or O=C(Me)(NEt2) are also reported.
Solutions of the latter three species and their respective ligands exhibit
spectra consistent with ligand exchange being in the fast exchange limit of the
n.m.r. time scale down to the lowest accessible temperatures.
Solanum alkaloids. XVIII. Utilization of solasodine for the preparation of nitrogen analogues of ecdysones
Authors: Cambie RC , Potter GJ , Read RW , Rutledge PS , Woodgate PD
Published: September 2010

Solasodine (spirosol-5-en-3β-01) (1) has been converted into (20S,22R,25R)-26-acetylamino-2β,3β,14α- trihydroxy-5β-furost-7-en-6-one
(41), a compound bearing ecdysone functionality in the steroidal nucleus aud
retaining the N-atom in the side
chain. The route involves dehalogenation of the bromohydrin (19), formed by
treatment of N,O-diacetylsolasodine (6) with N-bromoacetamide and perchloric acid as catalyst. The 2β-, 3β- and 14α-hydroxy groups are introduced by Woodward-Pr�vost
and selenium dioxide oxidations, respectively.
Calorimetric study of deuterium isotope effects in water-acetone systems
Authors: Khurma JR , Fenby DV
Published: September 2010

Molar excess enthalpies of
H20 + (CH3),CO, H20 + (CD3),C0, D20
+ (CH3)2C0 and D20+ (CD3)2CO
at 298.15 K are reported and, in the case of the first system, compared with
earlier studies. The results are comparable to those reported for deuterium
isotope effects in the molar excess enthalpies of other systems containing (CH3)2CO
and (CD3)2CO; they do not suggest the occurrence of any
deuterium exchange reactions. A calorimetric study of the mixing of (CD3)2CO
with H2O containing a small quantity of NaOH
indicates the occurrence of slow, exothermic reaction(s).
Molten potassium pyrosulfate: the reactions of alkali metal hydroxides, hydrogen carbonates and carbonates
Authors: Ford AN , Tariq SA
Published: September 2010

The reactions of hydroxides
of lithium, sodium and potassium; hydrogen carbonates of sodium and potassium
and carbonates of lithium, sodium and potassium with molten potassium
pyrosulfate were studied. It was found that during these Lux-Flood acid-base reactions,
hydroxides, hydrogen carbonates and carbonates reacted with pyrosulfate to
produce water, water plus carbon dioxide and carbon dioxide alone respectively,
as the gaseous products. Pyrosulfate, after accepting oxide ions from these
bases, was found in each case to be converted into sulfate. The temperatures
and stoichiometries of these reactions have been established.
The chemistry of titanium coupling agents
Authors: Coutts RSP
Published: September 2010

Modified titanium
alkoxides, which have been shown to be effective as coupling agents in the
preparation of wood-fibre reinforced cement composites, are described in this
publication. The synthesis and characterization of two previously unknown
alkoxides are reported together with some spectroscopic properties of the other
compounds.
Platinum-catalysed hydrogenolysis of phenol to benzene
Authors: Bagnell LJ , Jeffery EA
Published: September 2010

Benzene is obtained during
reduction of phenol by hydrogen in the presence of platinum black under mild
conditions.
Photoelectrolysis of water by use of thermally grown titanium oxide films
Authors: Hope GA , Morgan GG , McKenzie AR
Published: September 2010

The photoelectrolytic
properties of thermally formed titanium oxide layers on titanium have been
investigated for abraded and vacuum-annealed samples. The efficiency of
annealed electrodes depended upon the oxide thickness, showing a maximum near
200 nm. The observed increase in efficiency was noted mainly at shorter
wavelengths for annealed specimens. In all samples investigated, the
vacuum-annealed samples had the greatest photocurrent and lowest dark current.
Hydrogen abstraction from (2H3)methyl acetate by methyl and trifluoromethyl radicals
Authors: Arthur NL , Newitt PJ
Published: September 2010

A study of hydrogen
abstraction from CH3COOCD3 by CH3 radicals in
the temperature range 113-232�, and by CF3 radicals in the range
83-212�, has yielded data on the reactions: CH3+CH3COOCD3
→ CH4+CH2COOCD3 (1)CH3+CH3COOCD3
→ CH3D+CH3COOCD2 (2) CF3+CH3COOCD3
→ CF3H+CH2COOCD2 (3) CF3+CH3COOCD3
→ CF3D+CH3COOCD2 (4) The corresponding
rate constants, based on the values 1013.34 and 1013.36
cm3 mol-1 s-1 for the recombination of CH3
and CF3 radicals, respectively, are given by (k in cm3 mol-1 s-1 and E in J mol-1): logk1 = (11.31�0.12)-(43500�1030)/19.145T (1) logk1 = (11.31�0.12)-(53460�640)/19.145t (2) logk3 =
(11.12�0.06)=(34260�450)/19.145T
� (3) logk4 =(10.93�0.12)-(38650�900)/19.145T (4)These results lead
to kinetic isotope effects at 400 K for attack on the acetyl group of 11, for
the CH3 reaction, and 24, for the CF3 reaction, thus
confirming the values we obtained previously. For attack on the methoxy group,
the kinetic isotope effects are 8 and 4, for the CH3 and CF3
reactions, respectively.
Improved procedures for the degradation of gibberellic acid. The preparation of substrates for synthetic studies
Authors: Lombardo L , Mander LN , Turner JV
Published: September 2010

Gibberellic acid has been
efficiently degraded to methyl 16-oxo-17-norgibberellate (8), to
16-oxo-17-norgibberellin A1 methyl ester (9), and to (15), the 3α-epimer of (9). Both (9) and (15)
were protected as their acetal derivatives (10) and (16) respectively and
converted into the Δ2 olefin ent-10β,13-dihydroxy-16,16-ethylenedioxy-17,20
dinorgibberell-2-ene-7,19-dioic acid 7-methyl ester 19,10-lactone (11).
Experiments directed towards the synthesis of anthracyclinones. V. Double Claisen rearrangement of 1,4-Bis(allyloxy)anthraquinones
Authors: Cambie RC , Zhen-Dong H , Noall WI , Rutledge PS , Woodgate PD
Published: September 2010

The Claisen rearrangements
of 1,4-bis(prop-2'-enyloxy)anthraquinone (4) and 1,4-bis(2'-chloroprop-
2'-enyloxy)anthraquinone (3) in o-dichlorobenzene
have been examined. The former gives a low yield of
1,4-dihydroxy-2,3-bis(prop-2'-enyl)anthraquinone (22), and
1,4-dihydroxy-2-(prop-2'-eny1)- anthraquinone (5) as the major product. Also
formed is 1-hydroxy-4-propanoyl-2-(prop-2'-enyl)- anthraquinone (6) which
arises from an unprecedented rearrangement of one allyloxy group.
1,4-Bis(2?-chloroprop-2'-enyloxy)anthraquinone (3) gives mainly
2-(2'-chloroprop-2'-enyl)-4-(2'- chloroprop-2'-enyloxy)-1-hydroxyanthraquinone
(11) and a variety of minor products which are dependent on the time of
reaction. Treatment of compound (11) with ethanolic potassium hydroxide, followed
by a further Claisen rearrangement, gives a high yield of the synthetically
useful 4-(2'-chloro-prop-2'-enyl)-5-hydroxy-2-methyl-6,11-dihydroanthra[1,2-b]furan-6,11-dione (19).
Solanum alkaloids. XIX. Reactions of solasodine N,O-ditosylate
Authors: Cambie RC , Potter GJ , Rutledge PS , Woodgate PD
Published: September 2010

The utility of solasodine N,O-ditosylate (2) as a starting
material for ecdysone synthesis has been investigated. Reactions include epoxidation,
elimination and solvolyses.
Molten potassium pyrosulfate: the reactions of alkali metal oxides, peroxides, nitrites and nitrates
Authors: Ford AN , Tariq SA
Published: September 2010

The reactions of lithium
oxide, sodium peroxide, the nitrites of sodium and potassium, and the nitrates
of lithium, sodium and potassium with molten potassium pyrosulfate were
investigated. It was found that gaseous products of reactions of peroxide, nitrites
and nitrates consisted of, respectively, oxygen, nitrogen dioxide plus nitric
oxide, and nitrogen dioxide plus oxygen. Pyrosulfate, after accepting an oxide
ion from each of the above oxyanions, was converted into sulfate. The range of
temperatures and stoichiometries of these reactions have been established.
Micellar catalysis of nucleophilic aromatic substitution reactions between anionic nucleophiles and aromatic substrates containing anionic substituents
Authors: Broxton TJ
Published: September 2010

Rate constants for SNAr
reactions between anionic nucleophiles and aromatic substrates bearing anionic
substituents in the presence and absence of micelles of cetyltrimethylammonium
bromide (ctab) have been measured. Micellar catalysis of this class of reaction
seems to be of the same order of magnitude as for SNAr reactions
between anionic nucleophiles and dipolar organic substrates. Micellar catalysis
ofSNAr reactions of the
ambident nitrite ion has also been studied. The magnitude of catalysis of SNAr
reactions of sodium nitrite by micelles of ctab is large compared to that for SNAr
reactions of hydroxide ions or azide ions. This suggests that nitrite ion is
well solubilized by micelles of ctab and some consequences of this in
biological systems are discussed. The ambident behaviour of nitrite ion in
aqueous micellar solution towards organic substrates seems to mirror that in
methanolic solution.
Chemistry of the Podocarpaceae. LVI. Resin acids from Phyllocladus trichomanoides
Authors: Cambie RC , Grigor BA , Mee-Ing T
Published: September 2010

Five diterpenoid acids of
the labdane type have been isolated from the bled resin of Phyllocladus trichomanoides
by reversed-phase h.p.l.c.
Experiments directed towards the synthesis of anthracyclinones. VI. Claisen rearrangements of 1,4-Bis(prop-2'-enyloxy)anthraquinone
Authors: Cambie RC , Dunlop MG , Noall WI , Rutledge PS , Woodgate PD
Published: September 2010

The Claisen rearrangement
of 1,4-bis(prop-2'-enyloxy)anthraquinone (1) in N,N-diethylaniline and
acetic anhydride has been examined. New products include compounds (3), and (6)
and (14) in which a double bond has also migrated. Rearrangement of the compound
(3) in o-dichlorobenzene affords the
ketone (2), which supports an earlier mechanistic proposal.
A theoretical study of adduct formation between methanolate and Propan-2-one
Authors: Sheldon JC
Published: September 2010

Ab initio molecular orbital
calculations at the STO-3G level of approximation predict that the methoxide
anion bonds through its oxygen atom to form complexes with acetone in at least
three different ways: (i) A tetrahedral adduct at the
carbonyl carbon (ΔE -262 kJ mol-1).
(ii) A hydrogen-bond complex with a single hydrogen of one methyl group (- 100
kJ mol-1). (iii) A symmetrical bidentate hydrogen-bond complex with
a hydrogen from each acetone methyl group (- 143 kJ mol-1).
Compounds of the triphenyltin(II) ion
Authors: Bullard WR , Taylor MJ
Published: September 2010

Ionic compounds R+SnPh3-,
where R = Me4N, (Ph3P)2N, Na(15-crown-5) or
K(18-crown-6), are prepared from alkali metal derivatives, Ph3SnM,
by reactions in liquid ammonia which yield the products as yellow crystalline
solids, soluble in a weakly basic solvent. N.m.r. and vibrational spectra of
the Ph3Sn- anion, a pyramidal species with C3V
symmetry, and the cationic complexes [M(crown)]+, are reported and
assigned.
Condidymic acid, a new dibenzofuran from the lichen Cladonia squamosula
Authors: Chester DO , Elix JA
Published: September 2010

The dibenzofuran condidymic
acid (3-hydroxy-7-methoxy-1,9- dipentyldibenzofuran-2-carboxylic acid) has been
prepared by unambiguous synthesis and shown to co-occur with barbatic,
thamnolic and didymic acids in Cladonia squamosula.
Studies in heterocyclics: synthesis of 7-substituted 3-Phenyl-1H-imidazo[l,2-a]benzimidazoles
Authors: Soni RP
Published: September 2010

Some new 7-substituted
3-phenyl-1H-imidazo[1,2-a]benzimidazoles have been synthesized by the thermal
rearrangement of 3-(o-amino-substituted phenyl)-2-imino-4-phenyl-4-thiazoline.
A mechanism of formation of the products is suggested.
Micellar catalysis of the basic hydrolysis of N-methyl-N-(4'-nitropheny1)-2-phenoxyacetamide. Variation of the magnitude of catalysis for differentsources of hydroxide ions
Authors: Broxton TJ
Published: September 2010

The hydrolysis of
N-methyl-N-(4'-nitrophenyl)-2-phenoxyacetamide has been studied in the presence
and absence of micelles of cetyltrimethylammonium bromide. The micellar
catalysis depends on the reaction system being used. Hydrolysis in the presence
of sodium hydroxide, and in the presence of borate, carbonate/bicarbonate and
triethylamine/triethylammonium chloride buffers has
been examined. The magnitude of catalysis is shown to depend on the buffer
system used, the concentration of detergent, the concentration of the buffer,
the pH and the presence of any added salts. The results confirm that it is
unrealistic to compare independent sets of results on different compounds
unless the conditions for obtaining those results are identical. ��� Hydrolysis in the presence of
carbonate/bicarbonate buffers is shown to be subject to buffer catalysis and,
by analogy with results for p-nitrophenyl acetate, nucleophilic catalysis by
carbonate ions is suggested.
Compressibilities of aqueous electrolyte solutions
Authors: Leyendekkers JV
Published: September 2010

The Tammann-Tait-Gibson (TTG) model was used to derive and analyse an equation for the
isothermal compressibility of aqueous electrolyte solutions as a function of temperature and pressure.
The linear equation of Φk in c½ (Φk is the apparent molal compressibility, c is in mol 1-1) is shown
to be inadequate. The best function in the square-root of the concentration [either in (mol kg-1) or c]
is degree three. This gives the correct limiting slope predicted by the TTG model, viz., Sv/(BT + 1),
where S, is the Masson slope for apparent molal volumes and BT is the Tait parameter for pure
water. This slope was verified previously by comparison with the limiting slope obtained experi-
mentally, and can be predicted from the standard ionic entropies. The difference in the TTG slope
and the Debye-Hiickel point-charge slope is proportional to changes in the reorientation motion
of water molecules close to the ionic surface.
The electrostriction component, Vcelect, of the limiting partial molal volume is equal to
- K°(BT+ 1), where K° is the limiting partial molal compressibility. Values of V°elect calculated
from this relationship are compared with values from other models. The TTG model was used to
derive internal pressure functions which could be used to analyse deviations of V°elect from the
NIH (non-interacting homomorph) model.
The TTG equations were used to calculate the isothermal compressibilities of 15 electrolytes.
The agreement with experimental values is good (deviations are less than 0.1 × 10-6cm3 g-1 bar-1
for βv for the most reliable data). Values of Φk at 200 bar were calculated also and are in good
agreement with the corresponding experimental values.
Structural and spectroscopic studies of transition metal nitrite complexes. II. Crystal structures of cis-Bis(ethane-1,2-diamine)(nitrito-O,O')zinc(II) nitrite and trans-Bis[N,N-dimethyl(ethane-1,2-diamine)]dinitritozinc(II)
Authors: Finney AJ , Hitchman MA , Raston CL , Rowbottom GL , White AH
Published: September 2010

The crystal structures of
the complexes cis-bis(ethane-1,2-diamine)(nitrito-O,O')zinc(II)
nitrite and trans-bis[N,N-dimethyl(ethane-l,2-diamine)]dinitritozinc(II) are described. The former compound
contains one chelating nitrite, the second group being present as a counter
ion. In this complex the coordination polyhedron about the metal ion may be
described either as a distorted trigonal bi-pyramid
or an octahedron, depending upon whether the chelated
nitrite is considered to occupy one or two coordination sites. The second
compound is a trans nitrito complex, having an octahedral ligand geometry,
though with three markedly different metal-ligand bond lengths. The structures
of the complexes are compared with those of analogous nickel(II) nitrite
complexes, and the differences are discussed in terms of the electron
configurations of the two metal ions.
Structural and spectroscopic studies of transition metal nitrite complexes. X. Crystal structures of cis-Bis(2,2'-bipyridine)(nitrito-O,O')nickel(II) nitrate and hydrated Tris(2,2'-bipyridine)nickel(II) nitrite/nitrate and sulfate. Stereochemistry of the [M(bidentate ligand)2(bidentate ligand')1] system
Authors: Finney AJ , Hitchman MA , Kepert DL , Raston CL , Rowbottom GL , White AH
Published: September 2010

The crystal structures of
the title compounds are reported. In all cases, the coordination sphere of the
nickel atom comprises three bidentate ligands. In (1), [Ni(bpy)2(O2N)]
NO3, (Ni-N) is 2.M2 � although there are small
differences between those nitrogen atoms trans
to the nitrite oxygen atoms and the other two. (Ni-O) is 2.12 �. In (2),
[Ni(bpy)3] NO2/NO3,xH2O, and (3),
[Ni(bpy)3]- SO4,7.5H2O, a redetermination,
Ni-N is shown to be c. 2.09 �; serious disorder is present among the
non-cationic components of (2), precluding a definite assignment of
stoichiometry.
The solvolysis of 4-phenylbutyl p-nitrobenzenesulfonate in 2,2,2-trifluoroethanol and 1,1,1,3,3,3-Hexafluoropropan-2-ol
Authors: Ferber PH , Gream GE
Published: September 2010

Kinetic and product studies
show that 4-phenylbutyl p-nitrobenzenesulfonate solvolyses predominately via
the n-route in buffered 2,2,2-trifluoroethanol and
1,1,1,3,3,3-hexafluoropropan-2-ol; the extent of cyclization in the two
solvents is 69 and 99.5%, respectively. In buffered acetic acid, only 3.6%
cyclized product is obtained. The advantage of the use of the two fluorinated
alcohols for inducing π-participation during solvolysis is thus demonstrated.
Molecular quadrupole moment and magnetic anisotropy of carbon diselenide
Authors: Brereton MP , Cooper MK , Dennis GR , Ritchie GLD
Published: September 2010

Measurements of the
infinite-dilution molar Kerr constant, field-gradient birefringence constant
and Cotton-Mouton constant of carbon diselenide as a
solute in carbon tetrachloride at 298 K are reported. From an analysis of the
observations, the molecular quadrupole moment, Θ, and the magnetic anisotropy, ΔX,
emerge as (+15.4 � 2.7) × 10-40 Cm2 and (-19.6 � 2.6) × 10-5
J T-2 mol-1, respectively. Trends in these and related
electric and magnetic properties are considered for the sequence of six linear triatomic molecules of formula XCY (X,Y = O,S,Se).
Micellar catalysis of organic reactions. VII. The effect of the micellar counter ion in nucleophilic reactions of hydroxide and nitrite ions
Authors: Broxton TJ
Published: September 2010

The rates of basic
hydrolysis of N-methyl-N-(4'-nitrophenyl)octanamide and N,4-dimethyl-N- (3'-nitrophenyl)benzamide in the presence of
cetyltrimethylammonium fluoride and acetate and the SNAr reactions
of sodium nitrite with 2,4-dinitrofluorobenzene and 1-chloro-2,4-dinitrobenzene
in the presence of cetyltrimethylammonium fluoride have been measured and
compared to the rate in the presence of cetyltrimethylammonium bromide. The
identity of the micellar counter ion (i.e. fluoride, acetate or bromide) has only
a small effect on the rate of reaction despite quite substantial differences in
exchange constants for the appropriate nucleophile/counter ion pairs; this is
explained by a considerable amount of reaction between substrate molecules in
the micellar pseudophase and the nucleophile in the aqueous intermicellar
phase.
Substituent effects on electroreduction of the carbon-halogen bond
Authors: Abeywickrema RS , Della EW
Published: September 2010

Polarographic reduction of a series of 4-substituted
1-iodobicyclo[2,2,2]octanes has been examined in an
attempt to assess the effect of substituents on the half-wave reduction
potential. It is found that the values of E� do not show a linear
correlation with the relevant σ1 constants; the deviations are discussed in terms of the relative
importance of the steric and electric field effects of the substituent.
Controlled-potential electrolysis of a number of the substrates reveals that
the hydrocarbon corresponding to fission of the carbon-iodine bond is formed in
high yield.
Pigments of marine animals. XIV. Polyketide sulfates from the crinoid Comatula pectinata
Authors: Rideout JA , Sutherland MD
Published: September 2010

The polyhydroxyanthraquinones
known from the crinoid Comatula pectinata are shown to be present largely
as (fish repellent) sulfate monoesters. The sodium salt of the 3-O-sulfate of
4-butyryl-1,3-dihydroxy-6,8-dimethoxy-9,10-anthraquinone was isolated by its
chromatographic mobility on alumina in aqueous acetone or on sodium bicarbonate
in aqueous ethanol. The sulfate hydrolyses readily to the free phenol and is methylated (Me2SO4/K2CO3
in refluxing acetone) to 4-butyryl-1,3,6,8-tetramethoxyanthraquinone.
Methylated in the presence of tertiary alcohols
however, the sulfate ester resists cleavage, yielding the 1,6,8-trimethyl
ether, hydrolysable to 4-butyryl-3-hydroxy-1,6,8-trimethoxyanthraquinone.
A new vinyl acetylene from the red alga Laurencia thyrsifera
Authors: Blunt JW , Lake RJ , Munro MHG , Yorke SC
Published: September 2010

The isolation and
structural elucidation of a pair of new vinyl acetylenic
chloro diols (2a) and (2b)is presented.
Unfused heterobicycles as amplifiers of phleomycin. III. Thiazolylpyridines and bipyrimidines with strongly basic side chains
Authors: Brown DJ , Buttler BB , Cowden WB , Grigg GW , Kavulak D , Podger DM
Published: September 2010

Syntheses are described for
4-(thiazol-4'-yl)pyridines, each 2'-substituted by a dialkylaminoalkyl,
dialkylaminoalkylthio or dialkylaminoalkylamino
side chain; for 2- and 3-(thiazol-4'-yl)pyridines with a
2'-dimethylaminoethylthio substituent; for 4-(thiazol-2'-yl)pyridines with
either a 4'- or a 5'-dialkylaminoalkylcarbamoyl substituent; and for some
analogous compounds. The above and similarly substituted 2,4'-, 4,5'- and
5,5'-bipyrimidines have been screened for activity as amplifiers of
phleomycin-G against Escherichia coli B by an improved in vitro procedure. The results are tabulated and discussed.
The acid-catalysed rearrangement of (8R, l3R)-8,17-epoxylabd-14-en-13-ol; X-ray structure analysis of a tetracyclic ether product
Authors: Blunt JW , Ditzel EJ , Hartshorn MP , Hickey BJ , Johnstone PK , Munro MHG , Robinson WT
Published: September 2010

The structure and
stereochemistry of the tetracyclic ether (5) formed in
the acid-catalysed rearrangement of (8R,13R)-8,17-epoxylabd-14-en-13-ol (3) is
presented. Although vinyl group participation was involved it was by a
non-biosynthetic route.
Unfused heterobicycles as amplifiers of phleomycin. IV. 4,5'-Bipyrimidines with dimethylamino and/or dimethylaminoethylamino substituents
Authors: Kowalewski A , Strekowski L , Szajda M , Walenciak K , Brown DJ
Published: September 2010

The reaction of 5-bromo-N,N-dimethylpyrimidin-2-amine (1a) with butyllithium gives N,N,N',N'-tetramethyl-4,5'-bipyrimidine-2,2'-diamine
(2a). The known 4',6-dimethoxy derivative (3a) of this gives only 2,2'-bis(dimethylamino)-6-methoxy-4,5'-bipyrimidin-4'-one (4) on
attempted aminolysis by 2-dimethylaminoethylamine,
but the corresponding bismethylthio substrate (3b)
does undergo regular aminolysis at the 4'-position to
give the required product (34.2,2',4',6-Tetrakismethylthio-4,5'-bipyrimidine (5a)
undergoes similar aminolysis, first at the 4'- and
then at the 2'-position, to give the appropriate amines (5b) and (5c).
Structures are confirmed by n.m.r. and mass spectral studies. The products
showed little activity as amplifiers of phleomycin.
The application of the Hammett equation to 13C N.M.R. spectrometry. IV. Solvent effects
Authors: Happer DAR
Published: September 2010

The chemical shifts for Cβ of the vinyl group of styrene and 16 of
its meta-or para-substituted derivatives have been measured in seven solvents:
75% aqueous ethanol, ethanol, dimethyl sulfoxide, acetone, deuterochloroform,
carbon tetrachloride and benzene. Attempts have been made to correlate the data
by means of the Hammett equation, discrepancies being discussed in terms of
solvent dependence of σ and p.
New polychlorinated metabolites from a Barrier Reef collection of the sponge Dysidea herbacea
Authors: Erickson KL , Wells RJ
Published: September 2010

Four new polychlorinated
metabolites related to dysidenin and isodysidenin have been isolated from a small Barrier Reef
collection of the sponge Dysidea herbacea. It
has been shown that 13-demethyldysidenin and 13-demethylisodysidenin are
epimeric at C5 by direct comparison of the dechlorinated
derivatives of each.
The chemistry of pyrrolic compounds. XLIX. Further observations on the chemistry of the benzoporphyrins
Authors: Clezy PS , Mirza AH
Published: September 2010

Isomeric dibenzoporphyrins
having the fused rings attached to either adjacent or opposite pyrrolic rings
have been prepared and their properties compared. The chemistry of some of the
intermediates encountered during the synthesis of a benzoporphyrin has been
examined.
Copper(II) complexes of 3,3'-[Ethane-1,2-diylbis(imino)]bis(propanamide) in solution
Authors: Lim M
Published: September 2010

The interaction of
copper(II) ions with 3,3'-[ethane-1,2-diylbis(imino)]bis(propanamide) (H2eip)
in 0.1 mol l-l KNO3 at 25�C has been studied by means of spectrophotometry and potentiometry.
The acid dissociation constants of the ligand have
also been determined under the same conditions. Equilibria
(1) and (2) apply to the free ligand:
(H2eip)H22+KA↔(H2eip)H++H+(1)
(H2eip)H22+KA↔(H2eip)H+ (2)
For the copper complexes, equilibria (3)-(5) were found to hold:
Cu2+H2eip↔Cu(H2eip)2+ (3)
Cu(H2eip)2+↔Cu(H2eip)++H+ (4)
Cu(Heip)+↔Cu(eip)+H+ (5)
The values of the
equilibrium constants are: pKA 5.79, pKB 8.88, log K 11.89, pK'1
8.06, pK'2 9.48. The absorption maxima and the extinction
coefficients of Cu(H2eip2+ and Cu(eip)
are, respectively, γmax654 nm, εmax138 cm-1
mol-1 1 and γmax 543 nm, εmax 98.6 cm-1 mol-1
l.
Polyhydroxy biphenyl ethers from the brown alga Cystophora congesta
Authors: Gregson RP , Daly JJ
Published: September 2010

Two new phloroglucinol
polymers have been isolated from the aqueous extract of the brown alga
Cystophora congesta. They are the linear trimer
2,2',4,6,6'-pentahydroxy-1'-(3,5-dihydroxyphenoxy)- biphenyl ether (1)* and the
isomeric angular trimer 3,4',5,6'- or 3,3',5,5'-tetrahydroxy-2'-(3,4,5-tri-hydroxyphenoxy)biphenyl
ether which was characterized as its heptaacetoxy derivative (4). Structures
were elucidated principally from an analysis of 13C n.m.r. chemical
shifts and 13C-1H spin-spin coupling data. X-ray analysis
was performed on the heptaacetoxy derivative of (1) to distinguish it from a
regio-isomer (3).
Generalized van der Waals theory. XI. Gas solubility in simple fluids
Authors: Harrowell PR , Nordholm S
Published: September 2010

The generalized van der Waals theory of mixtures is
applied in the low solute concentration limit to the calculation of the Henry's
law constant KH, the partial molar enthalpy ΔH5, and
the partial molar volume V2. Several versions of the theory are used. Between-species
interactions are taken to obey Lorentz-Berthelot
rules. Comparison with experiment and earlier theory includes Ar, C6H6 and CCl4 solvents
and a number of solute species. At the lowest level of theory simple analytical
expressions for KH, ΔH5 and V2 are
obtained. The accuracy is semiquantitative with ΔH5
most in error. The accuracy is improved by allowing for the temperature and
density dependence of the effective hard-sphere diameter and the density
dependence of the excluded volume. The linear and bilinear mixing rules for the
excluded volume are compared and the former found preferable. No experimental
parameters (beyond accepted LJ(12-6) parameters) are used.
Pterins. VIII. The absolute configuration at C 6 of natural 2-Amino-6-[(1'R,2'S)- 1',2'-dihydroxypropyl]-5,6,7,8-tetrahydropteridin-4(3H)-one (L-erythro-5,6,7,8-tetrahydrobiopterin)
Authors: Armarego WLF , Waring P , Paal B
Published: September 2010

The
conformation of the side chain of 5,6,7,8-tetrahydrobiopterint (6) in 0.5 M DCl/D2O
is predominantly quasi-equatorial (deduced from 3J (13C4a, 1H6)
1.1 HZ), and is the same as that of the methyl group in 2-methyl-1,2,3,4-tetrahydroquinoxaline and in 2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3H)-one
in the same solvent. Because (-)-(2S)-2-methyl-1,2,3,4-tetrahydroquinoxaline(4)
and (-)-(6S)-2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3H)-one
(5) have the same conformation and negative c.d. spectra (O 248 nm and
263 nm respectively) as does the natural 5,6,7,8, tetrahydrobiopterin (O minimum
at 265 nm) in 0.1 M hydrochloric acid, then the
absolute conformations of the tetrahydropyrazine
rings and the absolute configurations
at the chiral centres C2, C6,
and C6 of compounds (4), (5) and (6) respectively are the same. Hence the
absolute configuration at C6 in natural 5,6,7,8
tetrahydrobiopterin is R.� A convenient synthesis of biopterin
on a gram scale is described.
The structure and function of oestrogens. III. 3,17β-Dihydroxy-6-oxaoestra-1,3,5(10),8(9)-tetraen-7-one and related steroidal coumarins
Authors: Caselli AS , Collins DJ , Stone GM
Published: September 2010

A Pechmann condensation of
resorcinol, or resorcinol monomethyl ether with ethyl t-7a-methyl- 1,5-dioxo-r-3a,4,5,6,7,7a-hexahydroindan-c-4-carboxylate
(10b) gave 3-hydroxy-6-oxaoestra- 1,3,5(10),8(9)-tetraene-7,17-dione (3a), or
the corresponding 3-methoxy compound (3b), respectively. Reduction of
3-hydroxy-6-oxaoestra-1,3,5(10),8(9)-tetraene-7,17-dione (3a) with sodium
borohydride gave 3,17β-dihydroxy-6-oxaoestra-1,3,5(10),8(9)-tetraen-7-one
(11). Compounds (3a) and (11) were tested for oestrogenic activity.