A convenient synthesis of 1, 1, 2, 2-tetramethylazetidinium perchlorate (2) and l-benzyl-1, 2, 2-trimethylazeti-dinium perchlorate (3) has been developed. The cyclization step in the sequence leading to these compounds involved treatment of 7-sec-aminoalkyl chlorides with silver perchlorate to afford the corresponding tertiary azetidine perchlorates in excellent yield. These were subsequently alkylated to give the quaternary azetidinium salts. l, l- ...