Homochiral 2,3-epoxy sulfides—powerful new synthetic building blocks providing stereoselective access to 2,3-epoxy sulfoxides, 2,3-dihydroxy sulfoxides and (E)-γ-hydroxy-α,β-unsaturated sulfoxides and sulfones. X-Ray molecular structure of rac-(2R*,3R*)-1-[(S*)-phenylsulfinyl] hexane-2,3-diol

Abstract

The stereoselective transformation of homochiral 2,3-epoxy sulfoxides into 2,3-epoxy sulfoxides is described. These intermediates undergo elimination under basic reaction conditions to give (E)-γ-hydroxy-α,β-unsaturated sulfoxides, and under Lewis acidic conditions form novel cyclic sulfoxonium salts which on hydrolysis give 2,3-dihydroxy sulfoxides with excellent stereochemical control. 2,3-Dihydroxy sulfoxides can also be converted into (E)-γ-hydroxy-α,β-unsaturated sulfoxides by elimination via a cyclic sulfite. The synthesis of (E)-γ-hydroxy-α,β-unsaturated sulfones by base-catalysed elimination of a 2,3-epoxy sulfone is also described.