Enol esters of 2-substituted-3-oxoalkanoates of (Z)-configuration were reduced by bakers' yeast to chiral 2-substituted-3-hydroxyalkanoates. The sy/f-selectivities of this reaction increased compared with those of the reduction of the corresponding racemic keto esters. The reaction mayproceed via an asymmetric hydrolysis of the enol esters, followed by the reduction of the resulting carbonyl gr...

the synthesis of twenty five esters of testosterone (17β -hydroxyandrost- 4-en-3-one) is described. all esters are derivatives of cycloalkycarboxylic acids. some of the esters possess α- , β -and/or & - substitution in the ester side-chain. the work was undertaken in order to evaluate long-acting male antifertility effect of such esters. most of the compounds, especially compound no.1, were fou...