trans-and cis-2-Diazo-1-(4-alkylcyclohexyl)-1-ethanones were reacted with arenesulfonic acids to afford the corresponding 2-(4-alkylcyclohexyl)-2-oxoethyl arenesulfonates. The esteraseinhibitory activity and hypolipidemic effect of the arenesulfonates were examined, and it was found that in most cases, the trans-isomers were more active than the corresponding cis-isomers. Stereoselective syntheses of several biologically potent trans- ...