反应详情

A suspension of (E)-benzyl 3-(((3S,6S,7R,8S)-8-benzyl-3-((tert-butoxycarbonyl)amino)-6-methyl-4-oxo-1,5-dioxonan-7-yl)oxy)acrylate (490 mg, 0.908 mmol, 1.00 equiv) and 10% Pd/C (48 mg, 0.045 mmol, 0.05 equiv) in EtOAc (9.1 mL, 0.1 M) was stirred for 16 h under an atmosphere of H2 (1 atm, balloon pressure) at room temperature. The reaction mixture was filtered through a plug of Celite® and the plug was washed with EtOAc (50 mL). The filtrate was concentrated to provide a white solid that was shown to be a mixture of partially reduced products by 1H NMR. This material was resubjected to the reaction conditions and isolated as before to provide 3-(((3S,6S,7R,8S)-8-benzyl-3-((tert-butoxycarbonyl)amino)-6-methyl-4-oxo-1,5-dioxonan-7-yl)oxy)propanoic acid (425 mg, 104%) as a white solid, contaminated with a small amount of EtOAc: IR (ATR) 3319, 2977, 2930, 2879, 1710, 1497, 1391, 1368, 1246, 1201, 1161, 1065, 851, 750 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.31-7.22 (m, 2H), 7.22-7.12 (m, 3H), 5.14 (d, J=8.2 Hz, 1H), 4.93 (dq, J=9.0, 6.4 Hz, 1H), 4.59 (dd, J=15.2, 7.4 Hz, 1H), 3.99-3.84 (m, 2H), 3.79 (dt, J=8.9, 6.1 Hz, 1H), 3.48-3.31 (m, 2H), 3.24 (dd, J=11.2, 7.5 Hz, 1H), 3.16 (t, J=9.0 Hz, 1H), 3.12-3.06 (m, 1H), 2.60 (t, J=6.1 Hz, 2H), 2.32 (t, J=12.6 Hz, 1H), 1.90 (s, 1H), 1.48 (d, J=6.4 Hz, 3H), 1.42 (s, 9H); 13C NMR (100 MHz, CDCl3) δ 176.37, 172.28, 154.99, 139.74, 129.16, 128.42, 126.13, 85.30, 80.17, 75.27, 72.78, 72.16, 67.35, 52.88, 47.20, 35.09, 28.27, 18.71; HRMS-ESI (m/z) [M+Na]+ calc'd for C23H33NO8Na, 474.2098. found, 474.2118.

1. filtrationThe reaction mixture was filtered through a plug of Celite®
2. washthe plug was washed with EtOAc (50 mL)
3. concentrationThe filtrate was concentrated
4. customto provide a white solid
5. additiona mixture of partially reduced products by 1H NMR
6. customThis material was resubjected to the reaction conditions
7. customisolated as before