Relative Rates of Base-Catalyzed Racemization and Deuterium Exchange of Aryl 2-Octyl Sulfones1

Abstract

The rates of base-catalyzed (sodium methoxide) racemization (krac) and exchange of deuterium for hydrogen (kexc) of phenyl and p-tolyl 2-octyl- 2-d-suifone in methanol at 100 deg were determined. The phenyl sulfone racemizes and exchanges more rapidly than the p-tolyl analog. With each sulfone, exchange exceeds racemization, kexc/krac is 17 for the phenyl suifone and 14 for the p-tolyl sulfone. Thus exchange occurs for the most part with preservation of optical configuration. This shows that carbanions stabilized by sulfone groups are nonplanar, enantiomeric suifones give enantiomeric carbanions.