Reaction Steps
Silver nitrate (1.43 g, 8.44 mmol) was added to a solution of Compound 315 (1.08 g, 2.11 mmol) in 48 mL of H2O-EtOH-THF (1:1:1) at 25° C. followed by stirring for 15 minutes. Potassium cyanide (0.962 g, 14.8 mmol) was then added and the mixture was stirred for one hour, concentrated in vacuo to 20 mL, poured into saturated aqueous sodium bicarbonate (30 mL), and extracted with dichloromethane (3×40 mL). The combined organic layers were dried (MgSO4) and evaporated in vacuo, and the residue was purified by flash column chromatography (silica, 35 percent ethyl ether in petroleum ether) to give 0.807 g (88 percent) of Compound 316: white foam Rf =0.22 (silica, 40 percent ethyl ether in petroleum ether); IR (CHCl3) νmax 3299, 2947, 1716, 1609, 1590, 1501, 1493, 1380, 1299, 1253 cm-1 ; 1H NMR (500 MHz, CDCl3 ) 7.96 (d, J=2.9 Hz, 1 H, aromatic), 7.38-7.07 (m, 6 H, aromatic), 6.89 (dd, J=8.9, 2.9 Hz, 1 H, aromatic), 5.88 (s, 1 H, H6), 5.77 and 5.74 (ABq, J=11.2 Hz, 2 H, olefinic), 3.81 (s, 3 H, OCH3), 3.16 (d, J=1.5 Hz, 1 H, C≡CH), 2.74 (dt, J=15.3, 5.0 Hz, 1 H, H9), 2.67 (ddd, J=15.3, 10.1, 6.1 Hz, 1 H, H9), 2.36-2.26 (m, 2 H, H7), 1.99-1.89 (m, 2 H, H8); 13C NMR (125 MHz, CDCl3) δ 201.5, 157.2, 154.1, 151.0, 129.3, 128.7, 128.5, 125.7, 124.1, 121.4, 120.4, 120.3, 114.8, 114.7, 90.6, 85.1, 82.7, 80.3, 74.9, 57.4, 55.5, 48.3, 38.8, 23.8, 18.6; MS (FAB+) m/e (rel intensity) 439 (M+, 100), 364 (8), 176 (19), 120 (10); HRMS for C27H21NO5 (M+), calcd 439.1420, found 439.1434.
