Asymmetric Synthesis of Chiral Flavanone and Chromanone Derivatives

Chiral chromans and flavanones derivatives are widely exist in plants, asymmetric synthesis of biological active chiral flavanone and chromanone derivatives is a valuable research field. A chroman derivatived (+)-(S,R,R,R)-Nebivolol (β1-adrenergic receptor blocker) has been synthesized by natural chiron and sulfoxide-directed method recently. Enantioselective method for the synthesis of flavanones and chromanones by the oxa-Michael addition and other cyclization reactions are described, asymmetric Michael-Michael cascade reaction for the construction of chiral chromans provideas a novel method in the synthesis of chiral flavanones and chromanones. Trost’s AAA reaction (Pd-catalyzed asymmetric allylic alkylation) provides a novel strategies in the synthesis of flavanones and chromanones.