Sequential asymmetric dihydroxylation and sulfoxidation of homoallylic sulfides. Stereochemical aspects of the preparation of new trifunctional chiral building blocks

Products with three new stereogenic centers were generated via sequential asymmetric dihydroxylation and sulfoxidation of homoallylic sulfides. The non-racemic homoallylic sulfoxides were prepared using chiral, vanadyl-based catalytic system with e.e. of up to 85%. Subsequently, these compounds were dihydroxylated with AD-mix system and gave products of low d.e.s (up to 40%). Recrystallization of l -diastereomers furnished both enantiomerically pure 1-phenyl-4-phenylsulfinylbutane-1,2-diols (X-ray), which are new and useful chiral building blocks. Further oxidation at sulfur produced the corresponding enantiomers of 1-phenyl-4-phenylsulfonylbutane-1,2-diol.