Reaction Steps
A solution of carbamate 60 (85 mg, 0.098 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 amine 61 (56 mg, 75%) as a white gum: 1H NMR δ 9.22 (t, J=5.8 Hz, 1H, CONH), 8.56 (d, J=1.7 Hz, 1H, H-2′), 8.46 (dd, J=4.8, 1.6 Hz, 1H, H-6′), 7.99 (br d, J=8.6 Hz, 2H, H-2, H-6), 7.89 (br d, J=8.6 Hz, 2H, H-3, H-5), 7.73 (dt, J=7.9, 1.9 Hz, 1H, H-4′), 7.68 (br d, J=8.3 Hz, 2H, H-2″, H-6″), 7.44 (br d, J=8.3 Hz, 2H, H-3″, H-5″), 7.36 (ddd, J=7.8, 4.8, 0.6 Hz, 1H, H-5′), 4.65 (s, 2H, CH2SO2), 4.51 (d, J=5.8 Hz, 2H, CH2NH), 3.49-3.50 (m, 20H, CH2O), 3.43-3.45 (m, 2H, CH2O), 3.33-3.36 (m, 2H, CH2O), 2.72 (t, J=7.3 Hz, 2H, H-r), 2.64 (t, J=5.6 Hz, 2H, H-21′″), 2.12 (s, 3H, CH3), 1.79 (br q, J=7.2 Hz, 2H, H-2′″), NH2 not observed; 13C NMR δ 165.4, 157.9, 149.8, 148.8, 148.5, 148.0, 135.7, 135.3, 135.1, 134.8, 129.1 (2), 128.7, 128.3 (2), 128.0 (2), 125.9, 125.3 (2), 123.4, 72.6, 69.7 (7), 69.6, 69.5, 69.4, 68.9, 52.8, 41.1, 40.4, 31.4, 30.4, 9.5; HRMS calcd for C39H53N4O10S (MH+): m/z 769.3477. found m/z 769.3492.
