Pummerer Rearrangement

The Pummerer rearrangement is a well-established rearrangement of a sulfoxide to an α–acyloxy–thioether, which has an array of useful synthetic implications. In the presence of an anhydride like acetic anhydride, the sulfoxide-O is acylated, which is rapidly eliminated to generate a thial intermediate 1. 1 is typically acylated to generate the desired α–acyloxy–thioether product; however, the thial can be interrupted by a wide array of nucleophiles and therefore has noted applications in total synthesis.