Lewis acid-catalyzed oxidative rearrangement of tertiary allylic alcohols mediated by TEMPO

Two methods for the oxidative rearrangement of tertiary allylic alcohols have been developed. Most of tertiary allylic alcohols studied were oxidized to their corresponding transposed carbonyl derivatives in excellent to fair yields by reaction with TEMPO in combination with PhIO and Bi(OTf)(3) or copper (II) chloride in the presence or not of oxygen. Other primary oxidants of TEMPO such as PhI(OAc)(2), mCPBA, and Oxone (R) were unsatisfactory giving the enone in modest to low yields. (C) 2009 Elsevier Ltd. All rights reserved.