... (C) The Chemical Society of Japan 1984 ADDITION REACTION OF TRIMETHYLSILYL AZIDE TOWARDS KETONES AND FACILE FORMATION OF TETRAZOLE DERIVATIVES Kozaburo NISHIYAMA* and Akio WATANABE Department of Chemistry, Tokyo Metropolitan University, Fukasawa, Setagaya, Tokyo 158 In the presence of Lewis acid such as SnCl2, the reactions ... Chem., 1975, 266; c) K. Nishiyama and H. Karigomi, Chem. Lett., 1982, 1477. ...