D-Galactopyranoside

Ragg (85) reported that no displacement of the tosyloxy function could be effected by treatment of methyl 2,3,6-tri-0-benzoyl-4-0-p-tolylsulfo-nyl-/ -D-galactopyranoside (20a) (or the 4-methylsulfonyl derivative 20b)... [Pg.173]

This indirect method of selective benzoylation at C-4 is of special interest in the galacto series (47). Reaction of methyl 4,6-O-benzylidene-a-D-galactopyranoside 97 with NBS afforded the corresponding 6-bromo-4-benzoate (98) in over 90% yield. The axial hydroxyl group at C-4... [Pg.193]

Methyl 2,3-di-0-acetyl-4,6-cyclo-4,6-dideoxy-p-D-galactopyranoside 2-Carb-35.2. Ring fusion methods... [Pg.145]

Trichloro-4,6,6 -trideoxygalactosucrose or6-chloro-6-deoxy-p-D-fructofuranosyl 4,6-dichloro-4,6-dideoxy-a-D-galactopyranoside ( galactosucrose is a trivial name for the 4-epimer of sucrose)... [Pg.149]

Methyl (sodium a-L-idopyranosyluronate)-(1 - 4)-(2-acetamido-2-deoxy-a-D-glucopyranosyl)-(1 ->4)-(sodium P-D-glucopyranosyluronate)-(1 ->3)-P-D-galactopyranoside... [Pg.154]

Treatment of suitably protected 2-triflates 220 and 222 of methyl ) -d-talopyranoside with Et4NF (MeCN, 50°, 30-50 min) gave, respectively, the 2-fluoro-y -D-galactopyranoside 221 (50%) and the unsaturated product 223 (74%). The mechanism was discussed. Acid-catalyzed hydrolysis of 221 (5... [Pg.131]

Direct conversion of the 6-sulfonates of D-galactopyranosides into their 6-deoxy-6-fluoro derivatives is usually hindered, because of the polar field-effect exerted by the lone electron pairs of the axial 0-4 (Ref. 158). Thus, the 6-0-mesylgalactoside 294 gave ° the 3,6-anhydro derivative 297 (23%) as the only isolated product on reaction with CsF in boiling ethanediol. How-... [Pg.140]

Abbreviations All, allyl MP, dimelhylaminopyridine or 2,4,6-trimelhylpyridine MOM, methoxy-methyl Piv, pivaloyl Tr, trityl other abbreviations are the same. Obtained accompanied with the 3,4-0-( methyl orthoacetyl)-a-D-galactoside the 0-deacetyl derivative was also reported. Inserted as a reference reaction. A mixture of two diastereoisomers. On hydrolysis (R = F), 3,6-dideoxy-3,6-difluoro-D-glu-copyranose is formed. Methanolysis gives methyl 3-deoxy-3-fluoro-a-D-galactopyranoside. [Pg.163]

As part of a study on the epitope of globoside, methyl 6-deoxy-6-fluoro-4-0-a-D-galactopyranosyl-) -D-galactopyranoside (613), and methyl 4-0-(4-deoxy-4-fIuoro- (614) and -6-deoxy-6-fluoro-a-D-galactopyranosyl)-)S-D-... [Pg.213]

Fig. 16.—Circular Dichroism of Methyl 2-Acetamido-2-deoxy-a-D-galactopyranoside...

Methyl 2-Acetamido-2-deoxy-/3-D-galactopyranoside (—), Methyl 2-Acetamido-2-... [Pg.96]

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