Abstract
The reaction of 2-dimethylamino-3,3-dimethyl-1-azirine 1 with carboxylic acids 2a-e at room temperature in inert solvents generates rearranged 1:1 adducts in 65-92% yields. These adducts are N-acyl derivatives of 2-amino-N,N-dimethyl-isobutyramide 3a-e resulting from 1,2 addition of the acid followed by 1,2 ring cleavage and transfer of an acyl group. Cyclic enolizable 1,3 diketones 4a-c react similarly with 1 to yield the corresponding rearranged 1:1 adducts 5a-c, whereas acyclic diketones or ethyl acetoacetate are inert under comparable experimental conditions.
Vittorelli, Piero