Study of the Lewis acid-promoted rearrangement of 2-aryl-2,3-epoxy acylates

The reaction of 2-aryl-2,3-epoxy acylates with Lewis acids was examined in detail. Cyclic 2-aryl-2,3-epoxy acylates afforded the rearranged products via the C2-carbocation intermediates obtained by the C2-cleavage of the oxirane rings. On the other hand, acyclic 2-aryl-2,3-epoxy acylates gave the rearranged products via the phenonium ion intermediates obtained by the C3-cleavage of the oxirane rings. The method was also applied to the synthesis of the optically active benzylic quaternary carbon center.