Intramolecular 1, 4-Dipolar Cycloadditions of Cross-Conjugated Heteroaromatic Betaines. Synthesis of Hexahydrojulolidines and Related Peri-and Ortho-Fused Ring …

KT Potts, T Rochanapruk, A Padwa…

Index: Potts, Kevin T.; Rochanapruk, Thevarak Journal of Organic Chemistry, 1995 , vol. 60, # 12 p. 3795 - 3805

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Citation Number: 33

Abstract

3-Alkenyl2-lactams react with (chlorocarbony1) phenylketene to give nonisolable anhydro-4- hydroxy-2-oxo-1, 3-oxazinium hydroxides which undergo regio-and stereospecific 1, 4- dipolar cycloaddition in moderate yields to produce cycloadducts containing a carbon dioxide bridge. Thermolysis of the cycloadduct led to extrusion of carbon dioxide via a nonconcerted 1, 5-hydrogen shift to give julolidinetype derivatives. Two of the ...