Mechanistic studies of the allylic rearrangements of [alpha]-silyloxy allylic silanes to silyloxy vinylic studies

Mechanistic studies have shown that the Lewis acid-promoted allylic rearrangement of [alpha]-silyloxy allylic silanes have proceeded along an ionic reaction pathway involving a contact ion pair. It is shown that the alleviation of steric congestion at the allylic position of the [alpha]-silyloxy allylic silane and stabilization of [[pi].cc] by hyperconjugation is the driving force behind this transformation.