THIOL/DISELENIDE EXCHANGE FOR THE GENERATION OF BENZENESELENOLATE ION - CATALYTIC REDUCTIVE RING-OPENING OF ALPHA,BETA-EPOXY KETONES

In the presence of N-acetylcysteine sodium salt, benzeneselenolate ion was generated in situ from diphenyl diselenide via thiol/diselenide and thiol/selenenyl sulfide exchange in aqueous methanal under mild conditions. Benzeneselenolate ion thus formed was efficiently alkylated and arylated to afford alkyl phenyl selenides and aryl phenyl selenides, respectively. alpha,beta-Epoxy ketones were catalytically reduced by benzeneselenolate ion to afford beta-hydroxy ketones (aldols) in goad yields. The. stereospecificity of the reaction was demonstrated in the preparation of optically active beta-hydroxyketones from chiral alpha,beta-epoxy ketones.