Reaction Steps
To a mixture of Compound 277 (1.28 g, 3.86 mmol), 3-[(tert-butyldiphenylsilyl)oxy]propyne (Compound 278, 1.48 g, 5.02 mmol), and diethylamine (800 mL, 7.73 mmol) in dry degassed N,N-dimethylformamide (7.7 mL) was added copper (I) iodide (74 mg, 0.39 mmol) followed by bis(triphenylphosphine)palladium(II) chloride (135 mg, 0.19 mmol). After being stirred in the dark for 11 hours under argon, the mixture was diluted with ethyl acetate (50 mL) and washed with saturated aqueous sodium bicarbonate (20 mL×2) and brine (20 mL). The organic layer was dried (Na2SO4) and evaporated in vacuo, and the residue was purified by flash column chromatography (silica, 10 percent ethyl ether in dichloromethane) to give 1.78 g (97 percent) of Compound 279: Rf =0.39 (10 percent ethyl acetate in dichloromethane); IR (film) νmax 3048, 2932, 2857, 2227, 1589, 1568, 1502, 1428, 1370, 1112 cm-1 ; 1H NMR (500 MHz, CDCl3) δ 8.59 (s, 1 H, H6), 7.95 (d, J=8.6 Hz, 1 H, H4), 7.92 (d, J=1.5 Hz, 1 H, H1), 7.84-7.78 (m, 4 H, aromatic), 7.53 (dd, J=8.6, 1.5 Hz, 1 H, H3), 7.48-7.39 (m, 6 H, aromatic), 4.62 (s, 2 H, C≡CCH2O), 3.04 (t, J=5.8 Hz, 2 H, H10), 2.87 (t, J=5.8 Hz, 2 H, H7), 2.01-1.93 (m, 2 H, CH2), 1.93-1.85 (m, 2 H, CH2), 1.12 (s, 9 H, t-Bu); 13C NMR (125 MHz, CDCl3) δ 152.8, 145.6, 141.0, 135.6, 133.1, 130.6, 130.2, 129.7, 129.6, 127.6, 127.5, 120.7, 88.4, 85.3, 53.2, 27.0, 26.7, 24.8, 22.2, 22.1, 19.2; MS (FAB+) m/e (rel intensity) 476 (M+H, 100), 418 (9), 388 (12), 220 (11), 197 (9); HRMS for C32H34NOSi (M+H), calcd 476.2410, found 476.2410.
