The influence of the oxidizing nucleophile on stereochemistry in the alkaline epoxidation of α,β-unsatured sulfones

✍ Scribed by Ruggero Curci; Fulvio DiFuria

• Book ID: 104243210
• Publisher: Elsevier Science
• Year: 1974
• Tongue: French
• Weight: 121 KB
• Volume: 15
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)92090-8

✦ Synopsis

THE epoxidation of a,B-unsatured carbonyl compounds by hydrogen peroxide in alkaline media is known to be non-stereospecific, yielding the same epoxide from either stereoisomaric 1.2 reactant.

Alkaline epoxidation of a,B-unsatured sulfones show similar features, as it was reported that treatment of &a-l-phenyl-Z-(p-tolylsulfonyl)ethene & or of its tm-isomer L' with alkaline hydrogen peroxide in aqueous acetone at 45" affords trune-epoxysulfone A. 3 SCHEME (1) " <p) d (2') Jr&p-Apparently, under these conditions (in the Scheme, Z = HO-), the initially formed carbanion adduct 1 has sufficient lifetime to undergo Ca-Cg rotational equilibration with the intermediate 2'. yielding the thermodynamically more stable epoxide 9.