Base-Mediated Claisen Rearrangement of CF3-Containing Bisallyl Ethers

We have previously clarified that the strongly electron-withdrawing CF3 group nicely affected the base-mediated proton shift of CF3-containing propargylic or allylic alcohols to afford the corresponding alpha,beta-unsaturated or saturated ketones, respectively, which was applied this time to the Claisen rearrangement after O-allylation of the allylic alcohols with a CF3 group, followed by isomerization to the corresponding allyl vinyl ethers via the proton shift, enabling the desired rearrangement in a tandem fashion, or in a stepwise manner, the latter of which was proved to have attained an excellent diastereoselectivity with the aid of a palladium catalyst.

Automated summary

The CF3 group was found to significantly influence the base-mediated proton shift in propargylic or allylic alcohols with high CF3 content, allowing for the synthesis of alpha, beta-unsaturated or saturated ketones. This method was applied to the synthesis of allyl vinyl ethers in this study, achieving the desired rearrangement through proton shift.