Tetrahedron letters

Synthesis of 5-methylene-1, 3-cyclohexadienes (o-isotoluenes) via electrocyclization of (4Z)-1, 2, 4, 6-heptatetraenes

KK Wang, Q Zhang, J Liao

Index: Wang, Kung K.; Zhang, Quan; Liao, Junkai Tetrahedron Letters, 1996 , vol. 37, # 24 p. 4087 - 4090

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Citation Number: 18

Abstract

Treatment of alkenyldicyclohexylborane 5 with 1-lithio-3, 4-pentadien-1-ynes derived from 10 followed by trimethyltin chloride and acetic acid furnished o-isotoluenes 13 in a single operation. The reaction proceeded through an initial formation of diene-allenes 11, which underwent facile electrocyclizations to produce 12 leading to o-isotoluenes 13.