Unprecedented alkene stereocontrol in the Claisen rearrangement of cyclic bis-allylic esters

by McFarland, Chris; Hutchison, John; McIntosh, Matthias C.

[GRAPHICS] The Ireland and ester enolate Claisen rearrangements of tertiary substituted bis-allylic esters derived from cyclohexenones afford pentenoic acids that possess tri- and tetrasubstituted alkylidenes with unprecedented levels of stereoselectivity. In some cases the higher energy exocyclic alkene is the major product.