Hydrolysis of the total cyanohydrin product obtained from several 3,5-methyl-substituted cyclohexanones yielded in each case only the hydroxy-acid with an equatorial carboxy-group. Oxidation of the mixture of ethynyl carbinols prepared from cis-3,5-dimethylcyclohexanone yielded predominantly the hydroxy-acid with an axial carboxy-group. Configurational assignments are based upon measurements of the dissociation constants and n.m.r. spectra of the hydroxy-acids and their O-acetyl derivatives. Both steric and kinetic arguments are presented to rationalize these results.