Stereoselective preparation of enaminone lithium dianions: Synthesis of N,N-Dimethylcarbamoylenaminones.
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.
SYNTHESIS OF PHENOLS BY THE INTRAMOLECULAR CONDENSATION OF β, β', δ, δ'-TETRAOXOALKANEDIOATES A NOVEL BF3-PROMOTED CLAISEN CONDENSATION OF ACETOACETATE DIANION WITH ESTERS AND AMIDES
The aromatization process of β,β', δ, δ'-tetraoxoalkanedioates, which were synthesized by the BF3-promoted Claisen condensation, was examined.