反应详情

To a solution of 3,4-di-O-acetyl-L-fucal (5.0 g) and lithium bromide hydrate (5.0 g) in acetonitrile (150 ml), activated resin prepared as in Example 1 (3.0 g) and water (6 ml) were added and stirred at room temperature for 15 min. The product was isolated as described for Example 1. Purification by chromatography on a column of Silica Gel using ethyl acetate-hexane (3:8) as eluant gave the title compound (4.0 g). α:β=9:4. [α]D20 =-57.6°±2°(c 1.03, CHCl3). 1H NMR δ: 5.45 (d, H-1α), 5.35 (m H-3α), 5.19 (H-4α), 5.10 (d, H-4β), 4.98 (m, H-3β), 4.87 (dd, H-1β), 4.33 (H-5α), 3.73 (m, H-5β), 2.04 & 1.86 (m, H-2). MS (calc. mass=232). Obs. m/e 231.13, 215.12, 155.09 (100%).

1. additionwere added
2. customThe product was isolated
3. customPurification by chromatography on a column of Silica Gel