Oxidative cyclization reactions: amide trapping groups and the synthesis of furanones.

Intramolecular anodic coupling reactions involving ketene dithioacetal radical cations and amide trapping groups have been examined. The reactions generate furanone products and benefit greatly from the addition of water to the reaction medium. The cyclization reactions lead to products having stereochemistry that is directly analogous to oxidative cyclization reactions utilizing ketene dithioiacetal radical cations and alcohol trapping groups. [reaction: see text]