Reaction Steps
A solution of Compound 225 (2.00 g, 4.77 mmol) in EtOH (80 mL) was hydrogenated over 10 percent Pd/C (1.00 g) under hydrogen atmosphere (ambient pressure) for four hours. The catalyst was removed by filtration through Celite with elution by 50 percent Et3N in THF (1.5 L). The combined filtrate was evaporated in vacuo to provide Compound 141a (1.40 g, 89 percent): white crystalline solid; mp 248°-250° C. (dec., from MeOH--Et3N); Rf =0.48 (silica, 3.2 percent methanol in dichloromethane); IR (KBr) νmax 3400, 2929, 2857, 1622, 1619, 1611, 1477, 1404, 1249, 1238, 1212, 1088, 1034, 838, 773 cm-1 ; 1H NMR (300 MHz, CDCl3) δ9.99 (br s, 1 H, ArOH), 8.52 (s, 1 H, H6), 7.91 (d, J=9.0 Hz, 1 H, H1), 7.20 (d, J=2.4 Hz, 1 H, H4), 7.14 (dd, J=9.0, 2.4 Hz, 1 H, H2), 5.43 s, 1 H, H10), 2.95-2.84 (m, 1 H, H7), 2.79-2.65 (m, 1 H, H7), 2.14-2.04 (m, 1 H, H8 or H9), 2.00-1.87 (m, 1 H, H8 or H9), 1.86-1.65 (m, 2 H, H8 or H9), 0.79 (s, 9 H, SiC(CH3), 0.00 (s, 3 H, SiCH3), - 0.02 (s, 3 H, SiCH3); MS (FAB+) m/e (rel intensity) 330 (M+H, 100), 272 (14), 198 (9); HRMS for C19H28NO2Si (M+H), calcd 330.1889, found 330.1890. Anal Calcd for C19H27NO2Si: C, 69.26; H, 8.26; N, 4.25. Found: C, 69.10; H, 8.17; N, 4.16.
