Formation Mechanism of Furfuryl Sulfides from O-Furfuryl Dithiocarbonates: Density Functional Theory Study for Aromatic [3,3]-Sigmatropic Rearrangement

摘要

Density functional theory (DFT) calculations at the B3LYP/6-31G(d) and B3LYP/6-31G+(d) levels demonstrated that O -furfuryl S -alkyl dithiocarbonate ( 1 ) undergoes aromatic [3,3]-sigmatropic rearrangement to the energetically unfavorable S -(2-methylene-2,3-dihydrofuran-3-yl) S -alkyl dithiocarbonate ( 2′ ), which then rearranges to furfuryl alkyl sulfide ( 3 ) with COS extrusion to regain the aromaticity lost in the first step.