Photochemical syntheses of 1, 2-diazepines. 11. Regiospecific synthesis of 1, 2-dihydro-1, 2-diazepin-3-ones

T Kiguchi, JL Schuppiser, JC Schwaller…

Index: Kiguchi, Toshiko; Schuppiser, Jean-Luc; Schwaller, Jean-Claude; Streith, Jacques Journal of Organic Chemistry, 1980 , vol. 45, # 25 p. 5095 - 5100

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Citation Number: 6

Abstract

Starting from 2-chloropyridine 1, a series of 1, 2-diazepin-3-ones 16 was prepared by a five- step synthesis. The key intermediates were the bicyclic oxadiazolium salts 10 which led, through a methoside ion induced ring opening, to the expected 2-methoxypyridinium ylides 11. The photoinduced ring enlargement of ylides 11 proved to be regiospecific and led to 3- methoxy-l, 2-diazepines, the immediate precursors of the final diazepinones 16.