Rearrangements of bridged diallenes. A facile synthesis of novel condensed heterocycles by tandem [3, 3]-sigmatropic rearrangement and double intramolecular …

S Braverman, M Freund

Index: Braverman, Samuel; Freund, Meir Tetrahedron, 1990 , vol. 46, # 16 p. 5759 - 5776

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Citation Number: 14

Abstract

Thienothiophene 14 and selenoloselenophene 16 have been synthesized by the action of lithium methoxide on τ, τ-dimethylallenyl thiocyanate and selenocyanate, respectively. A multistep mechanism involving bis-τ, τ-dimethylallenyl disulfide (20) or diselenide as key intermediates, is suggested. The latter are believed to undergo consecutive 3, 3]-sigmatropic rearrangement and double Michael addition, to the observed products. This mechanism is ...