Phosphine-Catalyzed Intramolecular Cyclizations of α-Nitroethylallenoates Forming (Z)-Furanone Oximes
A novel and efficient phosphine-catalyzed intramolecular cyclization of α-nitroethylallenic esters is reported. This process appears to be practical for the stereoselective syntheses of (Z)-furan-2(3H)-one oxime derivatives in excellent yields. Mechanisti