The [1,2] Wittig rearrangement of P-alkoxyalkyl ally1 ethers has been studied and found to provide syn-1,3-diol derivatives in 14-32% yield and with useful levels of diastereoselection.
The rearrangement of a-metalated ethers (Wittig rearrangement) has been of interest to investigators since its discovery in 1928, in part due to the mechanistic questions it has provoked.' In recent years the [2,3] Wittig rearrangement has proved to be an important synthetic method, allowing for the stereoselective formation of homo-allylic alcohols from the corresponding a-metalated ally1 ethers? The [1,2] Wittig rearrangement, in contrast, has not prospered in a similar manner presumably due to the lower yields associated with this reaction.3 In accordance with the general observations that have been made on this reaction, we have found the [1,2] rearrangement products of j.5alkoxyalkyl a//y/ ethers are obtained in ca. 20-30% yield. However,,a feature of these reactions that increases their attractiveness concerns the reaction diastereoselectivity: syrrl,3-diol derivatives are formed preferentially.4 Herein, we report on our investigations of this reaction class.