Galactopyranosyl chloride

Methyl 2,4-di-0-benzoyl-6-0-(bromoacetyl)-3-deoxy-3-lluoro-[Pg.172]

Azido-3-0-(2,3,4,6-tetra-0-acetyl-(i-D-galactopyranosyl)4,6-0-isopropylidene 2-deoxy-a-D-galactopyranosyl Chloride (24)... 

Methyl 5-acetamido-4,7,8,9-tetra-0-acetyl-3,5-dideoxy-D-glycero-a-D-galacto-2-nonulopyranosylonate)-(2—>3)-2,4,6-tri-0-benzoyl- -D-galactopyranosyl Chloride ("31)... 

Allylation of Pyranosyl Compounds with Allylstannane [19,20]. A solution of the methyl-(p-D-galactopyranosyl chloride) onate 22 (953.5 mg, 1.8 mmol) in 30 mL of dry, oxygen-free THF, was heated to 60°C. To this solution under nitrogen, were added the tributylallyl tin 23 (5.2 mL, 14.7 mmol) and A1BN (15 mg, 0.1 mmol). After 20 h, the solvent was evaporated, and the residue was taken up in 5 mL of acetonitrile. The acetonitrile layer was extracted with 20 mL of n-hexane and then concentrated. Chromatography on silica gel (toluene-acetone, 4 1) afforded the product 24 (889 mg, 93%), containing two anomers. Nuclear magnetic resonance (NMR) spectroscopy showed a ratio of the two anomers of 1.8 1. 

A mixture of 2-azido-3-0-(2,3,4,6-tetra-C>-acetyl-3-D-galactopyranosyl)-4,6-0-isopropyl-idene-2-deoxy-oi-D-galactopyranosyl chloride 24 (315 mg, 0.46 mmol), 237 mg (1.02... 

Austin and coworkers97 prepared a-D-gluco- (48) and -galactopyrano-sides, mainly, by the reaction of 2,3,4,6-tetra-O-benzyl-D-gluco- (47) and -galactopyranosyl chlorides (a mixture of the anomers) with 1,3-di-O-benzylglycerol in the presence of silver carbonate, silver perchlorate, and Drierite. 

Similarly, Suami and coworkers119 120 prepared rafflnose (64) (and planteose) derivatives, respectively, by the reaction of tetra-O-benzyl-a-D-galactopyranosyl chloride (62) with 2,3,4,l, 3, 4, 6 -hepta-0-acetylsucrose (63) (and 2,3,4,6,l, 3, 4 -hepta-0-acetylsucrose) in benzene in the presence of mercury(II) cyanide and Drierite. 

Several l-6>-sulphonyl derivatives of D-galactopyranose having a participating benzoyl or p-methoxybenzoyl group at 0-1 were synthesized from the corresponding D-galactopyranosyl chloride derivatives by use of silver toluene-p-... 

Tri-Ac, 6-tosyl 2,3,4-Tri-0-acetyl-6-O-tosyl-a-D-galactopyranosyl chloride C,9H23C10,oS 478.903... 

Tribenzyl, 2-Ac 2-0-Acetyl-3,4,6-tri-0-benzyl-x-D-galactopyranosyl chloride C29H31CIO6 511.013... 

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