“…After evaporation of the solvent, the crude product was purified by column chromatography (silica gel, CH/EtOAc 9:1) to yield dihydropyridine 18 a and pyridine 19 a. 1, 162.8, 162.0, 156.9, 155.6, 152.9, 144.9, 134.9, 133.7, 129.2, 127.8, 125.3, 125.1, 124.1, 118.0, 116.1, 115.4, 60.0, 56.9, 51.9, 21.4 197.4, 166.1, 164.8, 163.6, 153.0, 151.5, 138.3, 137.8, 134.7, 132.9, 126.1, 119.6, 119.2, 118.8, 53.5, 53.4 1, 156.7, 155.6, 152.7, 144.9, 135.0, 133.7, 129.2, 127.9, 125.4, 125.1, 124.1, 118.0, 117.1, 115.8, 68.6, 60.9, 56.8, 21.4, 15.6, 13.9 197.6, 164.4, 163.6, 153.5, 151.4, 138.3, 137.8, 134.5, 132.9, 126.2, 119.6, 119.1, 77.5, 77.2, 76.8, 62.8, 62.7, 14.2 (s,1 H),J = 8.4,2.0 Hz,2 H),7.52 (d,J = 0.8 Hz,1 H),J = 8.4,2.0 Hz,1 H),J = 8.4 Hz,1 H),J = 8.4 Hz,2 H),5.48 (s,1 H),4.33 (s,3 H),3.69 (s,3 H),2.38 (s,3 H), 2.17 ppm (s, 3 H); 13 C NMR (100 MHz, CDCl 3 ): d = 175. 2, 162.9, 162.1, 156.9, 153.9, 152.9, 144.9, 135.3, 135.0, 134.9, 129.2, 127.8, 124.7, 123.8, 117.7, 116.2, 115.1, 60.0, 56.9, 51.9, 21.3, 20.8 197.3, 166.2, 164.9, 161.6, 152.9, 151.4, 139.0, 138.2, 134.9, 132.4, 128.9, 126.2, 118.9, 118.5, 53.5, 53.4, 20.6 J = 8.4,2.0 Hz,2 H),J = 1.2,0.4 Hz,1 H),J = 8.4,2.4,0.4 Hz,1 H),J = 8.4 Hz,1 H),…”