Tetrahedron

Enamine chemistry-XXVI: The [4+ 2] cycloaddition reactions of 3-amino-1-(4-nitrophenyl)-prop-2-ene-1-thione with electrophilic olefins and acetylenes

JB Rasmussen, R Shabana, SO Lawesson

Index: Rasmussen,J.B.; Shabana,R.; Lawesson,S.O. Tetrahedron, 1982 , vol. 38, p. 1705

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Citation Number: 18

Abstract

Enamino-thiones 1 prepared from the corresponding enaminones by thiation with Lawesson's Reagent, were allowed to react with 2-chloroacrylonitrile and dimethyl acetylenedicarboxylate giving dihydro-2H-thiopyrans, 2, and 4H-thipyrans, 3, respectively. The reaction of 1a with ethyl propiolate at room temperature afforded 4H-thipyrans, 4a, which on standing rearranged to 2H-thiopyran, 5a (1, 3 amide shift). The reaction of 1b ...