Reaction Steps
A solution of 59 (0.52 g, 0.5 mmol) in methanolic sodium methoxide (0.007M, 40 ml) was left at room temperature for 2 h and sodium hydroxide (95 mg) in water (2 ml) was added. The mixture was hydrogenated (atm. pressure, Pd/C, 10%, 100 mg) for 100 min, filtered, neutralized with M hydrochloric acid and the solvent was removed. The residue was acetylated (acetic anhydride-pyridine 1:1, 100 ml) for 17 h at room temperature and then co-concentrated with toluene. The residue wa partitioned between dichloromethane (100 ml) and water (25 ml) and the organic phase was dried (Na2SO4) and concentrated. Column (5×18 cm) chromatography (SiO2, ethyl acetate:isooctane 2:1) gave amorphous 67 (300 mg, 62%) with [α]D21 +41° (c 1.0 chloroform). 1H-NMR (CDCl3, Me4Si) δ 5.91 (d, 1H, J=3 Hz, H4"), 5.40 (dd, 1H, J=11 and 3 Hz, H3"), 5.21 (t, 1H, J=9 Hz, H3), 5.18 (dd, 1H, J=11 and 3.5 Hz, H2"), 5.11 (dd, 1H, J=11 and 8 Hz, H2'), 4.99 (d, 1H, J=3.5 Hz, H1"), 4.88 (dd, 1H, J=9 and 8 Hz, H2), 4.73 (dd, 1H, J=11 and 2.5 Hz, H3'), 4.56-4.38 (5H, inter alia H1 and H1'), 4.23-4.03 (4H), 4.02 (d, 1H, J=2.5 Hz, H4'), 3.98-3.70 (3H), 3.69-3.46 (2H), 2.14-1.98 (MeCO), 1.19 (t, 3H, J=7 Hz, CH3--CH2). 13C-NMR (CDCl3, Me4Si) δ 170.4, 170.3 (4C), 169.9, 169.6, 169.5, 169.4, 168.7, 100.9, 100.1 (2d, J=160 and 164 Hz, Cl, Cl'), 99.4 (d, J=172 Hz, Cl"), 76.8, 76.3, 73.0, 72.6, 72.3, 71.6, (2C), 68.8, 68.6, 67.7, 66.9, 66.9, 65.4 (CH2), 62.1 (CH2), 61.2 (CH2), 60.1 (CH2), 20.8, 20.7, 20.54 (3C), 20.5 (2C), 20.46, 20.4, 20.3, 14.9.
