Reaction Steps
To a solution of tert-butyl((3S,7R,8R,9S)-7-(2-((tert-butyldimethylsilyl)-oxy)ethyl)-9-methyl-2-oxo-8-phenoxyoxonan-3-yl)carbamate (3.01 g, 5.77 mmol) in anhydrous THF (58 mL) was added a 1M solution of TBAF in THF (8.65 ml, 8.65 mmol). The resulting yellow solution was stirred at room temperature for 4 h, poured into 100 mL ½ saturated NaCl solution, and extracted with EtOAc (3×50 mL). The organic extracts were combined, dried over MgSO4, filtered, and concentrated to provide a light yellow oil, which was purified by column chromatography on SiO2 (5→25% acetone/hexanes) to provide the title compound as a hard white foam (1.95 g, 83%): 1H NMR (400 MHz, CDCl3) δ 7.44-7.17 (m, 2H), 6.95 (t, J=8.2 Hz, 3H), 5.17-4.98 (m, 2H), 4.29-4.11 (m, 2H), 3.75-3.53 (m, 2H), 2.28 (dt, J=13.4, 6.7 Hz, 1H), 2.03-1.88 (m, 1H), 1.88-1.74 (m, 2H), 1.74-1.62 (m, 1H), 1.62-1.48 (m, 2H), 1.44 (s, 10H), 1.28 (d, J=6.5 Hz, 3H), 1.26-1.19 (m, 1H), 1.14 (ddd, J=15.1, 7.5, 3.6 Hz, 1H); 13C NMR (101 MHz, CDCl3) δ 173.30, 159.23, 154.90, 129.69, 121.20, 115.33, 80.99, 79.92, 74.68, 60.96, 52.99, 39.55, 34.07, 28.56, 28.33, 19.13, 18.36; ESIMS m/z 408.3 ([M+H]+), 430.3 ([M+Na]+).
