A HIGHLY EFFICIENT AND RECYCLABLE CHIRAL DIRECTOR FOR ASYMMETRIC SYNTHESIS OF SULFOXIDES

Article abstract of DOI:10.1246/cl.1980.1595

The benzoxathiazine 2-oxide derivatives (2a-f) were prepared by reaction of the aminophenols (1a-f) with thionyl chloride in good yields.Equilibrium of 2a (R¹=α-C10H7, R²= CH3) with hydrogen chloride and subsequent reaction with phenylmagnesium bromide followed by action of methyl- or butyllithium gave (S)-(-)-4a or (S)-(-)-4b with high enantiomeric excess, respectively.