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 a,b-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.

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 migration reactions of CF3-containinig propargylic or allylic alcohols to afford the corresponding a,b-unsaturated or saturated ketones, respectively, which was applied this time to the Claisen rearrangement after O-allylation of the allylic alcohols, followed by isomerization to the corresponding allyl vinyl ethers, enabling the desired rearrangement in a tandem fashion, or in a stepwise manner where a palladium catalyst attained an excellent diastereoselectivity.

Modular synthesis of allyl vinyl ethers for the enantioselective construction of functionalized quaternary stereocenters

A flexible synthesis of allyl vinyl ethers, precursors of functionalized quaternary stereocenters, was developed by employing a regioselective Petasis olefination of haloallyl oxalates and subsequent cross-coupling with alkyl- and aryl boronic acids.

The first stereoselective total synthesis of neosemburin and isoneosemburin

The stereoselective total synthesis of neosemburin and isoneosemburin was achieved using 3-C-branched sugar precursors which in turn were synthesized by Claisen rearrangement of sugar derived allyl vinyl ethers.