Rhamnopyranoside 4-0-benzoyl-3-0-methyl

Me glycoside, 4-benzoyl Methyl 4-0-benzoyl-1 -thio-a-L-rhamnopyranoside [194347-74-5]... 

Selective dibenzoylation64 of methyl a-L-fucopyranoside (20) with benzoyl chloride-pyridine at a low temperature gave the amorphous 2,3-dibenzoate in high yield (80-85%) methyl 3-O-benzoyl-a-L-fuco-pyranoside was also isolated, in 6% yield. [Similar treatment of methyl 6-deoxy-a-L-mannopyranoside (a-L-rhamnopyranoside) gave the corresponding 2,3-dibenzoate in 50% yield, although, in this compound,... 

Methyl 2,3-isopropylidene-a-L-rhamnopyranoside was converted into the 4-tosyl derivative (LVII), from which the isopropylidene residue was removed by mild hydrolysis. Methylation then gave methyl 2,3-di-methyl-4-tosyl-a-L-rhamnopyranoside (LVIII), from which the reductive fission of the aromatic residue with sodium amalgam followed by hydrolysis gave 2,3-dimethyl-L-rhamnose (LIX).68 The same product was obtained by the substitution of benzoyl for tosyl, followed by methylation and separation on a column of cellulose.84 In an earlier synthesis,89 2,3-isopropylidene-L-rhamnose was converted into the 1,5-dibenzyl ether (LX) by treatment with benzyl chloride and potassium hydroxide. 

Selective benzoylation (and allylation) of methyl (and benzyl 4-O-benzyl-a-L-rhamnopyranoside (4) has been studied by phase-transfer catalysis and by activation via the tributyl stannate. The former reaction gave the 2,4-dibenzyl ether (5) in high yield, whereas the latter process gave mainly the 3,4-diether (6). An alternative means of obtaining the 2,4-diether (5) involved selective tritylation to give (7) followed by benzylation and removal of the trityl group. These dibenzyl ethers have been employed in the synthesis of the tetrasaccharide repeating unit of the immunodeterminant of Klebsiella serotype K36 polysaccharide. Similar results have been recorded for the selective benzylation of other 4,6-blocked a-mannosides. The syntheses of 3-O-benzyl-D-ribose, 2-0-benzyl-D-ribose, and l,6-anhydro-2,3,2, 4-tetra-0-benzyl-jS-lactose have been recorded. The latter was employed in the synthesis of lacto-A -tetraose. ... 

Glycosylation of methyl 2-0-benzoyl-a-L-rhamnopyranoside has led to a set of branched trisaccharides having P-D-gluco-, a-D-manno-, ot-L-rhamno-, and P-d-fructo-pyranosyl substituents at 0-3 and 0-4 of rhamnose. ... 

Dibenzoyl, 4-tosyl Methyl 2,3-di-O-benzoyl-4-O-tosyl-a-L-rhamnopyranoside [14686-85-2]... 

Benzyl 2,3-0-isopropylidene-a-D-lyxofuranoside, 1-70 Benzyl 2,3-0-isopropylidene-p-D-lyxofuranoside, L-72 Benzyl 2,3-0-isopropylidene-a-D-mannofuranoside, B-19 Benzyl 2,3-0-isopropylidene-a-D-mannopyranoside, B-19 Benzyl 2,3-0-isopropylidene-5-0-mesyl-a-D-lyxofuranoside, 1-70 Benzyl 2,3-0-isopropylidene-6-0-mesyl-a-D-mannofuranoside, B-19 Benzyl 2,3-0-isopropylidene-4-0-mesyl-a-L-rhamnopyranoside, B-20 Benzyl 3,4-0-isopropylidene-2-C-methyl-p-L-arabinopyranoside, M-229 Benzyl 3,4-0-isopropylidene-2-C-methyl-p-L-ribopyranoside, M-286 Benzyl 3,4-0-isopropylidene-2-0-methyl-p-D-ribopyranoside, B-21 Benzyl 3,4-0-isopropylidene-2-0-methyl-p-L-ribopyranoside, B-21 Benzyl 3,4-0-isopropylidene-p-D- /7// ro-pentopyranosid-2-ulose, P-42 Benzyl 2,3-0-isopropylidene-a-L-rhamnopyranoside, B-20 Benzyl 2,3-0-isopropylidene-p-D-ribofuranuronoside, R-146 Benzyl 3,4-0-isopropylidene-p-D-ribopyranoside, B-21 Benzyl 3,4-0-isopropylidene-p-L-ribopyranoside, B-21 Benzyl 3,4-0-isopropylidene-2-0-(2,3,4,6-tetra-0-acetyl-p-D-glucopyranosyl)-p-D-arabinopyranoside, G-284 Benzyl 2,3-0-isopropylidene-5-0-(2,3,4,6-tetra-0-acetyl-p-D-glucopyranosyl)-p-D-ribofuranoside, G-462 Benzyl 3,4-0-isopropylidene-2-0-tosyl-a-D-arabinopyranoside, B-14 Benzyl 3,4-0-isopropylidene-2-tosyl-p-L-arabinopyranoside, B-14 Benzyl 3,4-0-isopropylidene-2-0-(2,3,5-tri-0-benzoyl-a-L-arabinofuranosyl)-p-L-arabinopyranoside, A-801 Benzyl 3,4-0-isopropylidene-6-0-trityl-p-D-galactopyranoside, B-15... 

Methyl 4-0-acetyl-6-deoxy-2,3-0-isopropylidene-a-L-talopyranoside, D-372 Methyl 4-C-acetyl-6-deoxy-2,3-0-methylene-D-galactonate, A-15 Methyl 3-0-acetyl-2,4-diamino-2,4,6-trideoxy-a-D-idopyranoside, D-480 Methyl 5-0-acetyl-2,3-di-0-benzoyl-a-D-aral5inofuranoside, M-152 Methyl 3-0-acetyl-2,4-dibenzoyl-6-bromo-6-deoxy-a-D-altropyranoside, B-60 Methyl 4-0-acetyl-2,3-di-0-benzoyl-a-L-rhamnopyranoside, M-207 Methyl 4-0-acetyl-2,3-di-0-benzyl-a-L-fucopyranoside, M-183 Methyl 3-0-acetyl-2,4-di-0-benzyl-a-L-fucopyranoside, M-183 Methyl 2-0-acetyl-3,4-di-0-benzyl-a-L-fucopyranoside, M-183 Methyl 6-0-acetyl-2,3-di-O-benzyl-a-D-galactopyranoside, M-185 Methyl 6-0-acetyl-2,3-di-O-benzyl-a-D-mannopyranoside, M-204 Methyl 3- 0 -acetyl-2,4-dideoxy-2-dibenzyIamino-a-DL-/Areo -pentopyranoside, A-412... 

Methyl 2,6-di-0-benzoyl-3-0-methyl-p-D-mannopyranoside, M-205 Methyl 3,5-di-0-benzoyl-2-0-methyl-p-D-ribofuranoside, M-208 Methyl 4,6-di-O-benzoyl-2-0-methyl-3-O-tosyl-a-D-altropyranoside, M-149 Methyl 3,5-di-0-benzoyl-p-D-tAreo-pentofuranosid-2-ulose, P-45 Methyl 2,3-di-O-benzoyl-a-L-rhamnopyranoside, M-207 Methyl 2,4-di-O-benzoyl-a-L-rhamnopyranoside, M-207 Methyl 3,5-di-O-benzoyl-p-D-ribofuranoside, M-208 Methyl 2,3-di-O-benzoyl-l-thio-p-L-fucopyranoside, T-63 Methyl 2,3-di-O-benzoyl-l-thio-a-L-rhamnopyranoside, T-86 Methyl 2,3-di-0-benzoyl-5-0-tosyl-a-L-arabinofuranoside, M-152 Methyl 3,5-di-0-benzoyl-2-0-tosyl-p-D-lyxofuranoside, M-201 Methyl 2,3-di-0-benzoyl-4-0-tosyl-a-L-rhamnopyranoside, M-207 Methyl 2,4-di-0-benzoyl-3-0-(2,3,4-tri-0-acetyl-a-L-rhamnopyranosyl)-a-D-xylopyranoside, R-77... 

Ethyl 2-0-benzoyl-1-thio-a-L-rhamnopyranoside, T-86 Ethyl 4-O-benzoyl-l-thio-a-L-rhamnopyranoside, T-86 Ethyl 4-0-benzyi-2-0-methyl-l-thio-a-D-rhamnopyranoside, T-86 Ethyl 4-O-benzyl-l-thio-a-D-rhamnopyranoside, T-86 Ethyl 2,4-di-O-benzoyl-l-thio-a-L-rhamnopyranoside, T-86 Ethyl 2,3-O-isopropylidene-l-thio-a-D-rhamnopyranoside, T-86 Ethyl rhamnoside a-L-Furanose-/orm, E-27 Ethyl I-thicHX-L-rhamnopyranoside, T-86 Ethyl I-thio-p-L-rhamnopyranoside, T-86 Ethyl 2,3,4-tri-O-acetyl-l-thio-a-L-rhamnopyranoside, T-86 Ethyl 2,3,4-tri-0-acetyl-l-thio-(3-L-rhamnopyranoside, T-86 a-D-Fucopyranosyl-(l ->2)-a-L-rhamnopyranosyl-(l ->3)-i>mannose, F-159... 

Acetonitrile (high-performance liquid chromatography [HPLC] grade, HMD chemicals) was purified by passage through two columns of activated alumina under argon in a solvent purification system (Innovative Technology, Inc.). Methyl P-o-arabinopyranoside was purchased from Carbosynth methyl a-L-rhamnopyranoside was purchased from Alfa Aesar benzoyl chloride (>99%,... 

Methyl 2,3-0-benzylidene-4-C>-methyl-a-L-rhamnopyranoside reacted with NBS in carbon tetrachloride to give methyl 2-0-benzoyl-3-bromo-3,6-dideoxy-4-0-methyl-a-L-altropyranoside. This and the reactions of other benzylidene acetals with NBS, which were used in the synthesis of rare deoxy-sugars, are covered in more detail in Chapter 13. 

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