Tetrahedron Letters

Reaction of aryl-2-hydroxypropenoic derivatives with boron tribromide

R Dupont, P Cotelle

Index: Dupont, Romain; Cotelle, Philippe Tetrahedron Letters, 2001 , vol. 42, # 4 p. 597 - 600

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Citation Number: 11

Abstract

(Z)-Mono, di or trimethoxyphenyl-2-hydroxypropenoic acids 1a–d gave mixtures of (E) and (Z) mono, di or trihydroxyphenyl-2-hydroxypropenoic acids 2a–d when treated with boron tribromide. The isomerisation proceeds during the work-up and depends on the duration of the hydrolysis and the number of oxygens on the aromatic ring. When the aromatic ring was substituted with a methoxy group at the ortho position, a cyclisation occurs, and 3- ...