Methyllithium-promoted Wittig rearrangements of alpha-alkoxysilanes

[GRAPHICS] The Wittig rearrangements of alpha-alkoxysilanes, promoted by the action of methyllithium were studied. Depending on both the substrate and reaction c onditions employed, [2,3]-, [1,2]-, or [1,4]-Wittig rearrangements can be r ealized. These rearrangements were shown to be initiated by either Si/Li ex change or deprotonation alpha to the silane, Furthermore the sigmatropic sh ifts can often be followed by other synthetically useful in situ chemical e vents.