Alkynyliodonium salts in organic synthesis. Preparation of 2-substituted-3-p-toluenesulfonyldihydrofurans from 1-hydroxybut-3-ynyliodonium ethers viaa formal stevens shift of a carbon group

[GRAPHICS] p-Toluenesulfinate addition to 1-hydroxybut-3-ynyliodonium ethers triggers a sequence of reactions which ultimately delivers 2-substituted-3-p-toluene sulfonyldihydrofuran products along with 3-p-toluenesulfonyldihydrofuran as a major byproduct. A putative 1,2-alkyl shift within an unsaturated oxoniu m ylide (Stevens rearrangement) accounts for the oxygen-to-carbon transfer of the alkyl group.