Dithiols. Part 29. Syntheses of cis- and trans-2-phenyliminoperhydro-1,3-benzodithiole

Abstract

Reaction of trans-2-(phenylthiocarbamoylthio)cyclohexyl acetate and of trans-2-[(acetylthio)(phenylimino)-methylthio]cyclohexyl acetate with potassium hydroxide in ethanol gives trans-2-phenyliminoperhydro-1,3-benzodithiole. Overall retention of configuration is explained by the formation of an intermediate thiiranium ion. The same product, and the cis-isomer, are obtained when trans-perhydro-1,3-benzodithiole-2-thione and its cis-isomer, respectively, are successively treated with methyl iodide, aniline, and aqueous sodium hydroxide.