[reaction: see text] Generation and reactions of oxiranylanion 2 stabilized by a trifluoromethyl group are described. Treatment of (S)-2,3-epoxy-1,1,1-trifluoropropane (75% ee) with n-BuLi followed by electrophiles gave corresponding 2-alkylated epoxide 3 with retention of stereochemistry in moderate to good yields. The reaction is applicable for a general synthesis of optically active trifluoromethylated
1-trifluoropropane was converted into the corresponding oxiranylanion and reacted with electrophiles such as aldehydes, ketones and halides to give the corresponding adducts in moderate to good yields. The whole reaction occurred with retention of configuration at the stereogenic carbon center. In a similar manner, trifluoromethyl stabilizing aziridinylanions were generated from the optically active N-tosyl