TiCl4 mediated Michael addition reactions of α-cyanoketene-S,S-acetals with enones

Promoted by titanium tetrachloride, the Michael addition reactions of α-cyanoketene-S,S-acetals 1 with enones 2 led to the polyfunctionalized 2-[1,3]dithiolan-2-ylidene-3-substituted-5-oxo-5-substituted-pentanenitriles 3 in good to high yields.