Reaction Steps
To a mixture of (3S,7S,8S)-3-amino-7,8-bis(benzyloxy)-1,5-dioxonan-2-one (47 mg, 0.127 mmol), 3-hydroxy-4-methoxypicolinic acid (32.1 mg, 0.190 mmol) and HATU (80 mg, 0.202 mmol) in a vial were added CH2Cl2 (1.5 mL), followed by 4-methylmorpholine (0.083 mL, 0.759 mmol), and the resulting suspension was stirred at room temperature for 12 h. The resulting orange solution was directly purified by flash chromatography (SiO2) to afford the title compound as a white foam (32 mg, 48%): 1H NMR (400 MHz, CDCl3) δ11.90 (d, J=0.6 Hz, 1H), 8.61 (d, J=8.2 Hz, 1H), 8.49 (d, J=5.2 Hz, 1H), 7.43-7.24 (m, 11H), 6.86 (d, J=5.2 Hz, 1H), 5.03 (ddd, J=8.2, 6.8, 6.0 Hz, 1H), 4.80-4.62 (m, 5H), 4.21-4.07 (m, 2H), 3.93 (s, 3H), 3.85 (s, 1H), 3.79-3.65 (m, 2H), 3.55-3.47 (m, 1H); 13C NMR (101 MHz, CDCl3) δ 170.83, 168.92, 155.37, 148.76, 140.66, 137.97, 137.94, 130.17, 128.48, 128.43, 127.91, 127.89, 127.87, 127.81, 109.61, 81.52, 79.29, 73.80, 73.44, 73.24, 72.97, 63.91, 56.10, 52.25; ESIMS m/z 524.1 ([M+H]+).
