[3+2]-Cycloaddition reactions of 2-phenyliodonio-5,5-dimethyl-1,3-dioxacyclohexanemethylide

Abstract Iodonium ylide 2 , derived from dimedone, undergoes thermal [3+2]-cycloaddition with acetylenes and nitriles with Rh 2 (OAc) 4 to form the corresponding furans and oxazoles, respectively. Photochemically 2 reacts with various alkenes to form E -dihydrofuran derivatives.