Desymmetrization of 2,2',6,6'-tetrametoxybiphenyl by regioselective sulfenylation reaction

A practical regioselective sulfenylation reaction of the achiral title compound 1 provides desymmetrization and access to C2-symmetric sulphur derivatives. Resolution of 2,2,6,6-tetramethoxy-3,3-dimercapto-1,1-biphenyl 7 was achieved by conversion to the corresponding dithiocarbonate diastereomers. The absolute configuration of (aR)-(-)-7 and (aS)-(+)-7 was assigned unambiguously.