The cleavage of meso-epoxides with homochiral thiols:: synthesis of (+)- and (-)-trans-1-mercaptocyclohexan-2-ol

The synthesis of (+)- and (-)-trans-1-mercaptocyclohexan-2-ol is described. Ring opening of cyclohexene oxide with (-)-4-methoxybenzylnopan-3(R)-thiol 1a followed by oxidation gives two readily separable diastereomeric sulfoxides. These sulfoxides display very different thermal stability but both undergo regio-specific syn-elimination to give cyclohexan-1-ol-2-sulfenic acid that can be reacted in situ with 3,5-dimethylthiophenol to give a mixed disulfide. Reduction of these disulfides with lithium aluminium hydride gives the title compounds in enantiomerically pure form. (C) 1999 Elsevier Science Ltd. All rights reserved.