Feldman K S, Wrobleski M L
Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
J Org Chem. 2000 Dec 15;65(25):8659-68. doi: 10.1021/jo0011080.
The addition of p-toluenesulfinate to the silyl, 1-furanyl, and 1-pyranyl ethers of 1-hydroxybut-3-ynyl(phenyl)iodonium triflate triggers a sequence of reactions that ultimately delivers 2-substituted 3-p-toluenesulfonyldihydrofuran products in variable yields. A putative 1,2-group shift within an unsaturated oxonium ylide (Stevens rearrangement) accounts for the oxygen-to-carbon transfer of the ether substituent. Deuterium labeling studies clarify the mechanistic course of this shift by providing evidence consistent with intramolecular substituent transfer and by identifying the primary source of the proton that intercepts the ylide in the major yield-limiting process.