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

The synthesis of (+)-trans-2-mercaptocyclohexanol and (-)-trans-2-mercaptocyclohexanol was described. Ring opening of cyclohexene oxide with (-)-4-methoxybenzyl-3(R)-nopanethiol followed by oxidn. gives two readily separable diastereomeric sulfoxides. These sulfoxides display very different thermal stability but both undergo regio-specific syn-elimination to give 1-cyclohexanol-2-sulfenic acid that can be treated in situ with 3,5-dimethylthiophenol to give a mixed disulfide. Redn. of these disulfides with lithium aluminum hydride gives the title compds. in enantiomerically pure form.