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- ...
