Electronegatively substituted bicyclobutanes via the cycloaddition of trisubstituted electron-poor olefins to enamines
Abstract
Cycloaddition of trisubstituted electron-poor olefins such as trimethylethylenetricarboxylate to enamines such as N,N-dimethylisobutenylamine, quaternization, and base-induced elimination lead to electronegatively substituted bicyclobutanes such as trimethyl 4,4-dimethylbicyclobutane-1,2,2-tricarboxylate.