Synthesis of α-Benzyloxyannino-γ-butyrolactones via a Polar Radical Crossover Cycloaddition Reaction

A direct catalytic synthesis of substituted alpha-benzyloxyamino-gamma-butyrolactones is reported, starting from simple oxime acids and alkenes. The substituted O-benzyloxime acid starting materials are cyclized with oxidizable alkenes, via Polar Radical Crossover Cycloaddition (PRCC) reactions. The catalytic reaction is carried out using the Fukuzumi acridinium photooxidant and substoichiometric amounts of a redox-active cocatalyst. The utility of this method has been demonstrated through the use of 3 oxime acids and 19 oxidizable olefins.