Stereoselective and enantioselective synthesis of anti-1-(Trifluoromethyl) amino alcohols

anti-(Trifluoromethyl) beta-amino alcohols 2 have been prepared in good yields and with 90% diastereoisomeric excess through a reaction of 1-(trifluoromethyl) epoxy ethers 3 with dimethylaluminum amide, followed by the in situ chelation-controlled stereoselective reduction of the intermediate amino ketone. The salen-mediated chiral epoxidation of 1-(trifluoromethyl) enol ether 4a led to the homochiral epoxy ethers 11a and 12a in a good enantiomeric excess. Reaction with dimethylaluminum amide followed by a reduction step provided the chiral amino alcohols 15a and 16a, respectively.