Michael addition of benzoylacetonitrile to chiral α-cyanoacrylates derived from enantiomerically pure α-hydroxyaldehydes: Synthesis of 3-alkoxycarbonyl-4-alkyl-2-amino-5-cyano-6-phenyl-4H-pyrans

We describe the Michael addition of benzoylacetonitrile to α-cyanoacrylates 4a-c and 5a obtained from readily available chiral α-hydroxyaldehydes 1a-c . The resulting polyfunctionalized 4-alkyl-2-amino-4H-pyrans 6a-c, 7a have been obtained in good yield and moderate diastereoselectivity.