REACTIONS OF α-DIAZO-KETONES-V; ETHER OXYGEN PARTICIPATION IN THE ACETOLYSIS OF α'-PHENOXY- AND α'-DIPHENYLMETHOXY-α-DIAZO-KETONES

Article abstract of DOI:10.1016/S0040-4020(01)91950-7

The acetolysis of α-diazo-ketones 1a-d, 2 and 3a, b, c have been studied.The results obtained for 1a-d indicate that migration of the phenoxy group represents an important, alternative pathway to normal substitution only if a tertiary carbonium ion or a cyclic transition state, with the incipient positive charge located on a tertiary C atom, is involved in the reaction.Normal substitution was the only process in the case of 2 and 3a; instead, 3b and 3c gave in addition diphenylmethyl acetate and the corresponding 2-substituted-3-oxetanone, 17 and 19, produced by a cyclic mechanism involving the intermediate formation of oxonium ions 26b and 26c, respectively.