The Journal of Organic Chemistry

Mechanistic aspects of the annelation reactions of benzocyclobutenedione monoketals with vinyl organolithium reagents

LA Spangler, JS Swenton

Index: Spangler, Lori A.; Swenton, John S. Journal of Organic Chemistry, 1984 , vol. 49, p. 1800 - 1806

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Citation Number: 19

Abstract

Several mechanistic possibilities were considered. The first step is undoubtedly attack of the organolithium species 1 on the carbonyl group of 2 to produce 4, which has two obvious pathways available to it. A concerted, anion-accelerated [1, 3]-sigmatropic shift5 could occur, affording 5 directly. A second possibility is ring opening of 4 to form intermediates 6 or 7, which can cyclize to 5 via a Michael addition or electrocyclic ring closure, respectively ( ...