A Mild Method for the Efficient [3,3]-Sigmatropic Rearrangement of N,O-Diacylhydroxylamines
摘要:
A mild, general method for the [3,3]-sigmatropic rearrangement of N,O-diacylhydroxylamines, employing a combination of mild base and Lewis acid, is described. Employing stoichiometric amounts of reagents with respect to substrate provides alpha-acyloxyamides, whereas an excess of reagents favors formation of cyclic orthoamides.
N, O-Diacylhydroxylamines rearrange under basic conditions to afford 2, 3-disubstituted succinic acid derivatives. The rearrangement can be rationalized in terms of [3, 3]sigmatropic shifts of ester-amide dienolated N, O-diacylhydroxylamines.