An Efficient Synthesis of Enantiomerically Enriched Trifluoromethylated 1,2-Diols and 1,2-Amino Alcohols with Quaternary Stereocenters by Diastereoselective Addition of TMSCF₃ to Chiral 2-Acyl-1,3-perhydrobenzoxazines

TMSCF3 adds to chiral 2-acyl-1,3-perhydrobenzoxazines with total diastereoselectivity leading to quaternary trifluoromethyl alcohols. Further transformation of the addition products yields enantiomerically enriched trifluoromethylated 1,2-diols and 1,2-amino alcohols.