DMAP-catalyzed [4+2] annulation of α-substituded allenoates with unsaturated pyrazolones.

A DMAP-catalyzed [4 + 2] annulation of α-substituted allenoates with unsaturated pyrazolones has been achieved in dichloromethane at 40 °C, providing multisubstituted tetrahydropyrano [2,3-c]pyrazoles in good to excellent yields with moderate to good Z/E ratios. The allenoates worked as two-carbon synthons in the reaction. To create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Image 1 [ABSTRACT FROM AUTHOR]