Reaction Steps
0.5 g (0.99 mmol) of epothilone B are dissolved in 84 mL of CH2Cl2. After adding 43 μL (0.44 mmol) of piperidine and 127 μL (0.44 mmol) of titanium tetra-isopropylate, the reaction solution is strirred for 16 h at RT. After concentration In vacuo, the product is purified by FC (150 g of silica gel, CH2Cl2→CH2Cl2/acetone=4:1) giving a colorless oil: Rf (CH2Cl2/acetone=85:15): 0.57; M+H=508; 1H-NMR (500 MHz, DMSO-d6; δ/ppm): 9.56 (d, 1.5 Hz, 1H CHO), 7.37 (s, 1H, H19), 6.45 (s, 1H, H17), 5.31 (m, 1H, H15), 5.10 (d, 5.5 Hz, 1H, 3-OH), 4.13 (m, 1H, H3), 2.74 (m, 1H, H13), 2.64 (s, 3H, 20-Me), 2.53 (t, 7.5 Hz, 2H, H6), 2.36 (m, 1H, H8), 2.4/2.21 (m/m, 2H, H2), 2.06 (s, 3H, 16-Me), 1.98/1.77 (m/m, 2H, H14), 1.67/1.34 (m/m, 2H, H9), 1.45 (m, 2H, H10), 1.18 (s, 3H, 4-Me), 1 (s/s/s, 9H, 4-Me, 8-Me, 12-Me), 0.87 (t, 7.5 Hz, 3H, 6-Me).
