Stereospecific C-S bond formation from chiral tertiary alcohols by quinone-mediated oxidation-reduction condensation using alkyl diphenylphosphinites and its application to the synthesis of a chiral tertiary thiol

Oxidation-reduction condensation between 2-sulfanyl-1,3-benzothiazole (Btz-SH) and the alkyl diphenylphosphinites 1, prepared from tertiary alcohols, proceeded smoothly in the presence of 2,6-di-t-butyl-1,4-benzoquinone (DBBQ) and the corresponding S-alkylated products 2 were afforded in good yields. The stereo-inverted chiral Btz sulfides 2 were also produced stereospecifically by this condensation that used 1 derived from chiral tertiary alcohols. Subsequent removal of the Btz groups of 2 with t-BuLi or LiAlH4 provided a new synthetic route to chiral tertiary thiols and the structurally-related dialkyl sulfides.