Improved synthesis of trans-4-alkylcyclohexane carboxylic acids
Several stereomerically pure amino acid derivatives containing the N-terminal trans-4-alkylcyclohexanoyl fragment were obtained. Hydrogenation of 4-alkylbenzoic acids in the presence of a special Ru-Ni/C catalytic system and isomerization of the resulting mixture of trans- and cis-isomers of 4-alkylcyclohexanecarboxylic acids were used as the key steps. The stereomeric configuration of all compounds was confirmed by 1H NMR spectroscopy. The compounds obtained possess a broad biological activity potential and are useful intermediates in the synthesis of stereomerically pure modified peptides.
Bazurin, Alexey A.,Krasnikov, Sergey V.,Obuchova, Tatiana A.,Danilova, Angelina S.,Balakin, Konstantin V.
p. 6669 - 6672
(2007/10/03)
Long-acting androgenic compounds and pharmaceutical compositions thereof
Long-acting androgenic compositions comprising C 4 -C 6 cycloalkyl carboxylic acids of testosterone and a pharmaceutically acceptable carrier medium. The ester can be dissolved in an acceptable oily medium or suspended in an aqueous medium in the form of
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(2008/06/13)
ISOMERIZATION UNDER THE INFLUENCE OF p-TOLUENESULFONIC ACID.
The authors have investigated the influence of a mild acid isomerization catalyst, p-toluenesulfonic acid (TSA), on 4-butyl- (Ia) and 4-hexyl- (Ib) cyclohexanecarboxylic acids and their methyl esters (IIa, IIb). It is found that p-toluenesulfonic acid is an effective catalyst of cis-trans isomerization of 4-alkylcyclohexanecarboxylic acids and their esters; removal of water from the reaction medium raises the isomerization rate. Esters of alkylcyclohexanecarboxylic acids are isomerized at higher rates than the acids themselves. A probable mechanism of the acid-catalyzed isomerization reaction is proposed.
Kovshev,Karamysheva,Torgova,Geivandova,Roitman
p. 1069 - 1070
(2007/10/02)
HYDROGENATION OF 4-ALKYLBENZOIC ACIDS IN SODIUM ALCOHOLATES
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Kovshev, E. I.,Karamysheva, L. A.,Geivandova, T. A.,Roitman, K. V.,Torgova, S. I.
p. 2365 - 2367
(2007/10/02)
Long-acting contraceptive agents: Alphatic and alicyclic carboxylic esters of levonorgestrel