Unsaturated sulfoxides in organic synthesis: a new general pyrrole synthesis
Abstract
Pyrroles have been efficiently synthesised by a three-step reaction sequence. Michael addition of keto esters onto phenyl vinyl sulfoxide followed by Pummerer rearrangement gave the cyclic key intermediate 3. Mercury(II) salt induced carbon–sulfur bond cleavage afforded a 1,4-dicarbonyl equivalent 5. Treatment of the latter with an ammonium salt or a primary amine led to substituted pyrroles.