STUDIES OF REGIOSELECTIVITY AND STEREOSELECTIVITY IN SOME NUCLEOPHILIC RING-OPENING REACTIONS OF N-TOSYL-3-PHENYL-2-AZIRIDINEMETHANOLS AND DERIVATIVES

A study has been made of the regio- and stereoselectivity of the ring opening reactions of the 3-aryl substituted aziridines 1 and 2. The re giochemical outcome is apparently decided by a balance of electronic a ctivation at C-3 by the phenyl group and the chelating effects of C-l oxygen functionality which can direct nucleophiles intramoleculary to C-2 or C-3. Good levels of regiocontrol for either C-3 or C-2 attack a re obtained particularly for the reactions of aziridino alcohols la an d 2a with hydride reagents, while methyl-transfer reagents such as LiM e(2)Cu and AlMe(3) tend to give exclusive C-3 attack with inversion (c uprate) or inversion plus retention (trialkylaluminum). Possible react ion mechanisms (inter- vs. intramolecular) are discussed.