BASE-INDUCED REARRANGEMENT OF 1-(TRIMETHYLSILYL)ALLYLIC ALCOHOLS. STEREO- AND REGIOSELECTIVE SYNTHESIS OF SILYL ENOL ETHERS THROUGH LITHIUM HOMOENOLATES.

Article abstract of DOI:10.1021/ja00318a036

1-(Trimethylsilyl)allylic alcohols have been prepared and their conversions to silyl enol ethers have been examined. Under appropriate conditions, lithium alkoxides of the above alcohols are in equilibrium with lithium homoenolates, 3-(trimethylsiloxy)allyllithiums, which react with alkyl iodides to give the silyl enol ethers of defined stereo- and regiochemistry. Further, a catalytic amount of butyllithium induces the rearrangement of the alcohols to yield the corresponding silyl enol ethers in a highly stereo- and regiocontrolled manner via self-protolysis. Equilibrium composition between lithium alkoxides and lithium homoenolates has been shown to be greatly influenced by the steric factors around alpha carbons of allylic alcohols.