Three-component synthesis of dialkyl 2-(alkylimino-methylene)3- (2,2,5-trimethyl-4,6-dioxo-1,3-dioxan-5-yl)-succinates.

The adduct produced in the reaction between alkyl isocyanides and dialkyl acetylenedicarboxylates was trapped by 2,2,5-trimethyl-1,3-dioxane-4,6-dione (methyl Meldrum's acid), to afford highly functionalized ketenimines in good yields.