Reaction Steps
Lamellarin T (48 mg, 0.088 mmol) was dissolved in a solution of acetic anhydride (1.0 mL) and pyridine (1.0 mL) containing DMAP (several crystals) and the solution stirred at 18° C. for 26 h. The solution was then diluted with ethyl acetate (15 mL) and washed with NaHCO3 (a saturated solution in H2O, 20 mL) and citric acid (10% in H2O, 20 mL) dried over (MgSO4) and concentrated under reduced pressure. The residue was subjected to flash chromatography on silica gel (sequential elution with 2:1, 1:1 hexane/ethyl acetate) the relevant fractions (Rf 0.42 1:1 hexane/ethyl acetate) were concentrated giving the title compound (47 mg, 83%) as a white solid mp 251-2° C. IR (KBr disc, cm−1) 2937, 2840, 1769, 1718, 1603, 1545, 1507, 1475, 1456, 1414, 1295, 1266, 1201, 1141, 1117, 1036. 1H NMR (300 MHz, CDCl3) δ7.31 (dd, J=2.1, 8.4 Hz, 1H), 7.22 (d, J=2.1 Hz, 1H), 7.14 (d, J=8.7 Hz, 11H), 7.07 (s, 11), 4.90 (m, 1H), 4.60 (m, 1H), 3.90 (s, 3H), 3.89 (s, 3H), 3.45 (s, 3H), 3.39 (s, 3H), 3.13 (m, 2H), 2.30 (s, 6H). 13C NMR+APT (75.5 MHz, CDCl3) δ168.7 (C), 168.4 (C), 155.0 (C), 151.9 (C), 147.5 (C), 144.8 (C), 142.2 (C), 140.6 (C), 138.7 (C), 135.6 (C), 129.5 (CH), 127.6 (C), 127.2 (C), 125.4 (CH), 122.6 (C), 119.8 (C), 116.1 (C), 114.8 (C), 114.4 (C), 112.9 (CH), 111.7 (CH), 105.4 (CH), 105.0 (CH), 60.9 (CH3), 60.8 (CH3), 56.2 (CH3), 55.5 (CH3), 55.2 (CH3), 42.1 (CH2), 21.7 (CH2), 20.4 (CH3). MS (70 eV) m/z (%): 629 (53, M+•), 587 (100, M•−CH2CO); HRMS calcd for C34H3, NO11 629.1897. Found 629.1907.
