Reaction Steps
A solution of carbamate 62 (55 mg, 0.064 mmol) in a mixture of trifluoroacetic acid (2 mL) and anhydrous DCM (8 mL) was stirred at 20° C. for 1 h. The solvent was evaporated and the residue was purified by column chromatography, eluting with 10% MeOH/DCM containing 1% aqueous NH3, to give the amine 63 (38 mg, 78%) as a white gum: 1H NMR δ 9.18 (t, J=5.9 Hz, 1H, CONH), 8.01 (br d, J=8.6 Hz, 2H, H-2, H-6), 7.89 (br d, J=8.6 Hz, 2H, H-3, H-5), 7.79 (br d, J=8.5 Hz, 2H, H-2″, H-6″), 7.68 (br d, J=8.5 Hz, 2H, H-3″, H-5″), 7.33-7.34 (m, 4H, H-2′, H-3′, H-5′, H-6′), 7.22-7.28 (m, 1H, H-4′), 4.74 (s, 2H, CH2SO2), 4.49 (d, J=5.9 Hz, 2H, CH2NH), 4.45 (s, 2H, CH2C≡C), 3.62-3.65 (m, 2H, CH2O), 3.56-3.59 (m, 2H, CH2O), 3.50-3.52 (m, 16H, CH2O), 3.38 (t, J=5.7H, 2H, CH2O), 2.69 (t, J=5.5 Hz, 2H, H-21′″), 2.17 (s, 3H, CH3), NH2 not observed; 13C NMR δ 165.4, 158.1, 150.1, 139.5, 138.2, 135.7, 132.0 (2), 128.7, 128.6, 128.3 (2), 128.1 (2), 127.4, 127.2 (2), 126.8 (2), 125.7, 125.4 (2), 90.1, 84.1, 71.7, 69.8 (6), 69.7, 69.6, 69.5, 68.8, 58.0, 52.7, 42.7, 40.8, 9.7; HRMS calcd for C40H50N3O10S (MH+): m/z 764.3211. found m/z 769.3227.
