PREPARATION OF ENANTIOMERICALLY ENRICHED BROMOHYDRINS BY REACTION OF SULFOXIMINOOXIRANES WITH MGBR2 IN THE PRESENCE OF TETRA-BUTYLAMMONIUM BOROHYDRIDE

Treatment of enantiomerically pure N-tosylsulfoximinooxiranes 6 with MgBr2 in the presence of tetra-butylammonium borohydride gives enantiomerically enriched bromohydrins 3, together with small amounts of the simple primary alcohols. The bromohydrins are isolated in good yields with enantiomeric excess in the range 70% to 91% (as assessed by enantioselective g.l.c.).