DBU-mediated Ireland–Claisen rearrangement of allyl alk-3-enoates: an efficient synthesis of 2-ethylidene-γ, δ-unsaturated carboxylic acids

Y Li, A Goeke, R Wang, Q Wang, G Fráter

Index: Li, Yunxia; Goeke, Andreas; Wang, Ruiyao; Wang, Quanrui; Frater, Georg Tetrahedron, 2007 , vol. 63, # 39 p. 9605 - 9613

Full Text: HTML

Citation Number: 3

Abstract

Ireland–Claisen rearrangement, triggered by silyl enolization of allylic but-3-enoates 2, has been developed using DBU as the base in the presence of an excess amount of TMSCl under reflux in acetonitrile for a couple of hours. The procedure allows the synthesis of a range of 2-ethylidene-γ, δ-unsaturated carboxylic acids 5 in moderate to high yields. It is further revealed that the rearrangement proceeds equally well with allylic (E)-hexa-3, 5- ...