A solution of DCC (4.54 g, 22 mmol) dissolved in the minimum of CH2Cl2 was added dropwise to compound 73 (6 g, 0.020 mol) in CH2Cl2 at −5C, whilst stirring, with a catalytic amount of DMF (10 drops). The reaction mixture was stirred for a further five minutes before HOBt (3.0 g, 22 mmol) in CH2Cl2 was added. The reaction mixture was allowed to stir for 1 hour at −5° C., then left to stir for 12 hours at room temperature. The colourless precipitate of DCU was removed by filtration and the remaining reaction mixture cooled to −5° C. (S)-pyrrolidinemethanol (2.37 mL, 24 mmol) was added and the reaction mixture allowed to warm to room temperature and, stirred for 12 hours. TLC (70% Pet ether/EtOAc) revealed reaction completion. The reaction mixture was washed with NaHCO3 (4×100 mL), NH4Cl (4×100 mL), H2O (4×100 mL), brine (4×100 mL) and dried over MgSO4. Purification was achieved via flash column chromatography (60% pet ether/EtOAc) to furnish compound 74 as a stiff brown oil (95%). 1H NMR (250 MHz, CDCl3); δ 8.69 (s, 1H, NH), 8.13 (d, 1H, J=8.2 Hz, aromatic H), 7.42-7.22 (m, 6H, Coc aromatic H and aromatic H), 7.06 (ddd, 1H, J=1.07, 7.6, 7.5, aromatic H), 6.70 (d, 1H, J=16 Hz, 3′-H), 6.34 (dt, 1H, J=6.4, 18 Hz, 2′-H), 4.81 (dd, 2H, J=1.1, 6.4, 1′-H), 4.40 (br, s, 1H, H-11a), 3.85-3.42 (m, 4H, H-11, H-3), 2.06-1.70 (m, 4H, 1-H, H-2); 13C NMR (62.9 MHz, CDCl3) δ 171.3 (ester carbonyl), 136.6 (aromatic quat), 134.6 (methine), 131.3 (methine), 129.0 (methine), 128.5 (methine), 128.0 (methine), 127.1 (methine), 123.9 (alkenic methine), 122.7 (methine), 121.3 (methine), 67.0 (Coc, C-1), 66.2 (methylene Coc), 61.1 (methine, C-11a), 51.9 (methine, C-3), 28.8 (methine, C-1), 25.5 (methine, C-2); MS m/z; 381 (M+. +1), 363, 337, 308, 279, 261, 247, 229, 203, 117.
