C([O:9][C@H:10]1[C@:14]([F:16])([CH3:15])[CH:13]([O:17][CH3:18])[O:12][C@@H:11]1[CH2:19][OH:20])(=O)C1C=CC=CC=1.CO>N>[F:16][C@@:14]1([CH3:15])[CH:13]([O:17][CH3:18])[O:12][C@H:11]([CH2:19][OH:20])[C@H:10]1[OH:9](2R,3R,4R)-4-fluoro-2-(hydroxymethyl)-5-methoxy-4-methyl-tetrahydrofuran-3-yl benzoate (about 18 g, 63.3 mmol) in methanolic ammonia solution (25% w/w, 360 ml) was stirred at room temperature for about 36 hours, completion of the reaction monitored by thin-layer chromatography and methanol was removed under reduced pressure. Water added to the reaction mixture and extracted with ethyl acetate, the organic layer was dried over sodium sulphate and concentrated under reduced pressure. Purification by silica gel column chromatography using 20% ethyl acetate: hexane eluded the title compound (8 g) as an off-white solid. Yield: 70%; 1H NMR (300 MHz, CDCl3): δ 4.79 (d, 1H, J=10.8 Hz), 4.01-3.97 (m, 2H), 3.85 (d, 1H,), 3.71-3.66 (m, 1H), 3.44 (s, 3H), 2.05 (brs, 1H, —OH), 2.02 (brs, 1H, —OH), 1.47 (d, 3H, J=23.4 Hz); Mass: [M+Na]+: 203 (100%); IR cm−: 3437, 3372, 3294, 2924, 1459, 1102, 1049, 1006, 821, 731.
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