A-Alkylazetidines werc: cleaved by riucleophilic reagents under moderate conditions t o give the corresponding ;l-substitrited-propylaInines. The additions were subject t o acid catalysis and also proceeded slowly under alkaline SNZ conditions. , I I he effects of ring strain and substituents on the reactivity o f small heterocycles are of continuing interest. Although the four-membered nitrogen heterocycles had generally heen considered t o lack entirely the wellestablished alkylatirig activities of aziridiries and aziridinium salts ( I ) , several groups of workers have recently demonstrated the alkylation of nucleophiles by various azetidinium cations (2). 'I'he reactions were slower or required more vigorous conditions as would be predicted from a smaller ring-strain energy for the four-membered ring. However, these ring cleavages were not different in kind lrom those involving the three-membered cycles. We now report unequivocal examples of similar reactions of tertiary azetidines ( 3 ) .