Stereoselective preparation of enaminone lithium dianions: Synthesis of N,N-Dimethylcarbamoylenaminones.

Article abstract of DOI:10.1016/S0040-4020(97)00320-7

A simple regio- and stereoselective synthesis of N'N-dimethylcarbamoylenaminones 2 by acylation of enaminone lithium dianions 1' with N,N-dimethylcarbamoyl chloride is reported. The mechanism for the stereoselective preparation of the enaminone lithium dianions 1' and successive acylation was investigated. The carbamoylenaminones 2 are selectively cyclized to 4-amino-2-pyranones 3 or hydrolyzed to carbamoyl diketones 4 in acidic conditions.