A new stereoselective synthesis of (E)-α-β-Unsaturated-γ-dicarbonyl compounds by the Henry reaction

Abstract

(E)-Enediones are valuable intermediates for the synthesis of important molecules such as prostaglandins, rethrolones, perfume, pheromone, macro cycle, and other natural products. Considerable attention has been paid to methods for the synthesis of these compounds, in particular the ring cleavage of 2-mono or 2,5-disubstituted furans. This transformation can be performed by several different oxidative methods,but these methods suffer from certain drawbacks, such as regioselective alkylation of the furan before the ring cleavage, the use of potentially explosive reagents, severe reaction conditions, and formation of mixtures of (E)- and (Z)- isomers or exclusive formation of the (Z)-isomer, which requires a strong acid for isomerization to the (E)- compound. The preparation of the (E)-enedione system via alternative methods thus is important.