반응 단계
A solution of N-[(3S,7S,8R,9S)-7-benzyl-8-isobutoxy-9-methyl-2-oxo-1,5-dioxonan-3-yl]-3-hydroxy-4-methoxy-pyridine-2-carboxamide (25 mg, 0.05 mmol) in THF (1.2 mL) was passed through an H-cube bench top hydrogenator (5% Rh/C catalyst, 100° C., 100 bar H2, 1 mL/min). The reaction mixture was concentrated to furnish N-((3S,7 S,8R,9S)-7-(cyclohexylmethyl)-8-isobutoxy-9-methyl-2-oxo-1,5-dioxonan-3-yl)-3-hydroxy-4-methoxypicolinamide as a white solid (21 g, 83%): mp 89-92° C.; 1H NMR (400 MHz, CDCl3) δ 11.97 (s, 1H), 8.60 (d, J=8.2 Hz, 1H), 7.99 (d, J=5.2 Hz, 1H), 6.86 (d, J=5.2 Hz, 1H), 5.07-4.85 (m, 2H), 4.07 (dd, J=11.7, 7.1 Hz, 1H), 3.93 (s, 3H), 3.60 (dd, J=10.3, 3.3 Hz, 2H), 3.57-3.45 (m, 1H), 3.35 (dd, J=8.3, 6.3 Hz, 1H), 3.23 (dd, J=8.3, 6.6 Hz, 1H), 2.96 (t, J=9.0 Hz, 1H), 1.91-1.53 (m, 9H), 1.45 (d, J=6.4 Hz, 3H), 1.37-1.08 (m, 6H), 0.92 (dd, J=6.7, 3.3 Hz, 6H); 13C NMR (101 MHz, CDCl3) δ 171.0, 169.9, 155.3, 148.7, 140.6, 130.3, 125.5, 109.6, 85.0, 79.0, 76.1, 72.6, 56.1, 51.8, 42.7, 36.4, 34.9, 32.5, 30.3, 29.2, 26.6, 26.5, 26.2, 19.6, 19.5, 18.9. ESIMS m/z 493.0 ([M+H]+).
