Isomerization of Allyl Ethers Initiated by Lithium Diisopropylamide

Lithium diisopropylamide (LDA) promotes virtually quantitative conversion of allylic ethers to (Z)-propenyl ethers. It was discovered that allylic ethers can be isomerized efficiently with very high stereoselectivity to (Z)-propenyl ethers by LDA in THF at room temperature. The reaction time for the conversion increases with more sterically hindered allylic ethers. Different amides were also compared with LDA for their ability to effect this isomerization.