Aldolase-catalyzed C-C bond formation for stereoselective synthesis of nitrogen-containing carbohydrates

摘要: Rabbit muscle aldolase was found to catalyze stereoselective aldol addition of dihydroxyacetone phosphate (1) 3-azido-2-hydroxypropana(2 ). The ketose 1-phosphates were isolated as barium salts, 4a/4b, and hydrolyzed with acid phosphatase. mixture 6-azido-6-deoxy-D-fructose(5) 6-azido-6-deoxy-L-sorbose thus obtained separated by anion-exchange chromatography. Reductive amination 5 6 yielded, respectively, 1-deoxymannojirimycin (7) 1-deoxynojirimycin (8), high diastereoselectivity (>98:2). Analogous 1 3-azido-2-hydroxybutanal( 9)( E:Z = 92:8) afforded a the 6-azido-6,7-dideoxyheptuloses 12 13, which contained 88% 6-azido-6,7-dideoxy-D-altro-heptulose(13 After chromatography, 13 18:82 β/α anomers. pure gave 2,6,7-trideoxy-2,6-imino-D-glycero-D-manno D-gluco-heptitol (14 15) (3:2 molar ratio), likewise If hydrogenated under identical conditions, 2,6,7-trideoxy-2,6-imino-L-glycero-L-gulo-heptitol(16) could be besides 14 15.