Wittig rearrangement of allyl furfuryl and allyl thienyl ethers and sulfides and their benzo-derivatives
Treatment of allyl furfuryl ethers and sulfides with butyllithium results in metallation at the free α-position of the heterocycle, with partial Wittig rearrangement to the isomeric alcohols and sulfides and ring opening. With the benzo-derivatives, Wittig rearrangement and ring opening takes place.