Reaction Steps
Boc-Puromycin analog 4A (392 mg, 0.63 mmol) was dissolved in a 1:1 TFA (5 mL) and CH2Cl2 (5 mL) mixture and then stirred at room temperature for 30 min. Volatiles were evaporated in vacuo and the residue was dissolved into CH2Cl2. The solution was poured into a suspension of saturated aqueous NaHCO3. The organic layer was dried over Na2SO4 and evaporated to dryness in vacuo. The residue was purified by flash chromatography (SiO2, step-wise gradient from 2-15% MeOH in CH2Cl2) to afford Puromycin analog 5A (151 mg, 46%) as a white solid. 1H NMR (600 MHz, DMSO-d6): δ 8.45 (1H, s), 8.24 (1H, s), 8.06 (1H, br), 7.17 (2H, d, J=8.4 Hz), 6.87 (1H, d, J=8.4 Hz), 6.14 (1H, d, J=4.8 Hz), 5.98 (1H, d, J=2.4 Hz), 5.14 (1H, t, J=5.4 Hz), 4.42-4.52 (2H, m), 4.14 (2H, t, J=5.4 Hz), 3.92-3.97 (1H, m), 3.10-3.80 (12H, m), 2.92 (1H, dd, J=13.8, 5.4 Hz), 2.55 (1H, dd, J=13.8, 9.0 Hz), 1.72 (2H, br); 13C NMR (150 MHz, DMSO-d6): δ 174.8, 156.5, 154.3, 151.8, 149.6, 137.9, 131.1, 130.3, 119.6, 114.2, 89.4, 83.6, 79.1, 73.2, 66.7, 61.0, 56.3, 50.0, 49.6, 40.1; MS (ESI, m/z): 527 (M+H)+.
