alpha-D-Xylofuranose, 1,2:3,5-bis-O-(1-methylethylidene)- → 1,2-O-isopropylidene-alpha-D-xylofuranose
反応式
CC1(C)[O:7][C@@H:6]2[C@H:8]3[O:13][C:12]([CH3:15])([CH3:14])[O:11][C@H:9]3[O:10][C@@H:5]2[CH2:4][O:3]1.O=C[C@@H]([C@H]([C@@H](CO)O)O)O>OS(O)(=O)=O>[CH3:14][C:12]1([CH3:15])[O:11][C@@H:9]2[C@@H:8]([C@@H:6]([OH:7])[C@@H:5]([CH2:4][OH:3])[O:10]2)[O:13]1参加物
4
実験手順
1,2:3,5-Di-O-isopropylidene-D-xylofuranose (70.66 g, 0.30 mol) is treated with H2SO4 (0.1 M, 300 mL). Upon stirring, the xylose slowly dissolves. After 30 minutes, the reaction is quenched with NH4OH (pH 9.0) and half of the water removed at reduced pressure. The aqueous layer is diluted with brine (100 mL) and extracted with ethyl acetate (3×200 mL). A normal work-up provides an oil. Kugelrohr distillation provides 1,2-O-isopropylidene-D-xylofuranose (40 g, 68.5%); b.p. 120-135° C./0.4 mm Hg.