Methyl 4,6-0-benzoyl-2,3-0-isopropylidene

The following abbreviations are used in this and the subsequent tables Ac for acetyl, Pr for propionyl, Bu for butyryl, Bz for benzoyl, Ts for tosyl, My for methylene, Ed for ethylidene, Bd for benzylidene, Fd for furfurylidene. Id for isopropylidene, Me for methyl, Et for ethyl, Be for benzyl, Tr for trityl and Az for azoyl. Where the linkages of acetals and ketals are known, they are shown by different type fonts.)... 

Primary alcohol groups in several protected ribo-, fructo- and glucofuranoses including 2,3,4-tri-O-benzoyl-D-glucose, 1,2-isopropylidene-D-xylo-furanose, 2,3 4,5-di-0-isopropylid-ene-D-fructopyranose, methyl 2,3-O-isopropylidene-P-D-ribofuranoside, l,2-0-isopropylidene-3,5-0-benzylidene-D-glucofuranose and... 

Stoicheiometric RuOyCCl was also used to oxidise several furanoses, partially acylated glycosides and l,4 3,6-dianhydrohexitols [317] pyranosides to pyrano-siduloses [313] methyl 2,3,6-tri-O-benzoyl-a-D-glucopyranoside and its C-4 epimer to the a-D-xy/o-hexapyranosid-4-ulose (Table 2.3) [317], and methyl 2,3,6-trideoxy-a-D-e 7f/tro-hexapyranoside to the -a-D-,g/yceri9-hexa-pyranosid-4-ulose, an intermediate in the synthesis of forosamine [318], It was also used to oxidise benzyl 6-deoxy-2,3-0-isopropylidene-a-L-mannopyranoside to the a-L-/yxo-hexapyranosid-4-ulose [319] and for oxidation of isolated secondary alcohol functions, e.g. in the conversion of l,6-anhydro-2,3-0-isopropylidene-P-D-man-nopyranose to the-P-D-/yxo-hexa-pyranos-4-ulose mannopyranose (Fig. 2.16, Table 2.3 [20, 320, 324]). 

Only relatively few displacements of chloro groups in carbohydrate derivatives have been reported. Treatment of 6-chloro-6-deoxy-l,2 3,5-di-O-isopropylidene-a-D-glucofuranose (22) with anhydrous hydrazine for 2 days at reflux temperature yielded the corresponding 6-deoxy-6-hydrazino derivative.47 The chloro group in methyl 6-chloro-6-deoxy-a-D-glucopyranoside could be displaced by a benzoate group to afford methyl 6-O-benzoyl-a-D-glucopyranoside, in 74% yield, by... 

Compound 177 was purified through the corresponding methyl /3-L-glucopyranoside by treatment with methanol, ether, and silver carbonate (overall yield 42%). The same reaction was applied186 to methyl 5-0-benzoyl-2,3-0-isopropylidene-a-D-lyxofuranoside (178), which gave the bromide 180 (crude yield 98%). Evidently, com-... 

Fucitol, 2,3 4,5-di-O-isopropylidene-1-O-acetyl-1-O-benzoyl-1-O-p-tolylsulfonyl-Fuconie acid, amjde, 3-O-methyl-Fucono-l,4-lactone, 3-O-methyl-... 

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