Strict base dependence of chirality transfer on [2,3]-Wittig rearrangement of 1,1,2-trifluoroallylic ether

Investigation of [2,3]-Wittig rearrangement of optically active 1,1,2-trifluoroallylic ether revealed that chirality transfer of the starting compound strictly depended on the base employed, while stereoselectivity of the newly formed olefinic part was controlled with perfect (E)-selectivity. Because the reaction was inhibited by addition of TEMPO; these results suggested [2,3]-Wittig reaction proceeded via a radical pathway mechanism.