Reaction Steps
To a 50 mL high pressure reactor with a magnetic stir bar was added (3S,6S,7R,8R)-8-benzyl-3-(tert-butoxycarbonylamino)-6-methyl-4,9-dioxo-1,5-dioxonan-7-yl isobutyrate (400 mg, 0.863 mmol) in THF (3 mL) to give a colorless solution. To the solution was added 5% Rh/C (50 mg, 0.024 mmol). After the reactor was sealed, it was purged with hydrogen gas (4 times). The reactor was charged to approximately 600 psi of H2 at room temperature (about 22° C.) and then the reaction was warmed to 70° C. and stirred at for 6 h. The reaction mixture was cooled, filtered, and concentrated. The residue was purified via column chromatography (SiO2, hexanes/EtOAc gradient) to afford the title compound (414 mg, 92%) as an off-white solid: 1H NMR (400 MHz, CDCl3) δ 5.32 (dd, J=39.3, 12.3 Hz, 2H), 5.01 (t, J=9.9 Hz, 1H), 4.94-4.72 (m, 2H), 3.58 (s, J=51.8 Hz, 1H), 2.72-2.51 (m, 2H), 1.78-1.52 (m, 6H), 1.45 (s, J=6.0 Hz, 9H), 1.26 (d, J=6.3 Hz, 3H), 1.20 (dd, J=7.0, 3.0 Hz, 6H), 1.19-1.04 (m, 4H), 1.02-0.68 (m, 3H); 13C NMR (101 MHz, CDCl3) δ 175.50, 172.74, 154.78, 133.68, 123.39, 80.39, 75.22, 74.50, 67.85, 65.49, 51.47, 47.36, 35.85, 35.40, 34.05, 34.01, 32.09, 28.19, 26.28, 26.00, 25.87, 18.95, 18.82, 17.77; ESIMS m/z 492 ([M+Na]+).
