An asymmetric synthesis of a 4-substituted-1,4-dihydropyridine

A concise, convergent asymmetric synthesis of the 4-substituted-1,4-dihydropyridine 1 [Ohnmacht, C. J., Jr.; Trainor, D. A.; Forst, J. M.; Stein, M. M.; Harris, R. J. Patent No. 5,622, 964] has been achieved via a novel asymmetric Michael addition of an optically pure vinylogous amide to an α,β-unsaturated ketone. The overall process is three steps from readily available starting materials and provides an economical manufacturing route to the title compound, which was required as a candidate drug for the treatment of urinary incontinence.