Base-Catalyzed domino double michael reactions of 1-hydroxy-1,4-dien-3-ones and 2-alkylidenemalononitriles: A diastereoselective route to polysubstituted 3-alkanoyl-4-hydroxycyclohex-3-enes

The diastereoselective synthesis of 2,6-disubstituted 3-alkanoyl-4-hydroxycyclohex-3-ene-1,1-dicarbonitriles has been developed through domino double Michael addition of 1,5-disubstituted 1-hydroxy-1,4-dien-3-ones to 2-alkylidenemalononitriles catalyzed by triethylamine. This simple domino process affords a variety of highly functionalized 3-alkanoyl-4-hydroxycyclohex-3-enes, some of which are not easily accessible using other methodologies, in moderate to good yields and excellent diastereoselectivity (dr > 95:5). Thus, the generality of this process and feasibility of introducing bioactive moieties make this reaction highly valuable in synthetic and medicinal chemistry.