Iodine-Catalyzed Aerobic Oxidation of Spirovinylcyclopropyl Oxindoles to Form Spiro-1,2-dioxolanes Diastereoselectively.

A novel method of iodine-catalyzed aerobic oxidation with spirovinylcyclopropyl oxindoles under mild conditions has been described. A series of spiro-1,2-dioxolanes were prepared in good to excellent yields and considerable diastereoselectivities. The new approach is operationally simple, scalable, and tolerant of various functional groups.