Methyl glucosides degradation

A further degradation of methyl a-n-glucoside by the action of barium hypobromite was observed by Bergmann and Wolff. From 12 g. of the glycoside, 4.6 g. of glyoxylic acid benzylphenylhydrazone was obtained. The experimental conditions differed from those used in the preparation of menthol a-D-glucuronide in that about twice as much bromine was used. 

Alkaline degradation of periodate-oxidized methyl 4,6-0-benzylidene-a-D-glucoside (123) with lime-water gave equal amounts of glycolic acid and 4-formyl-2-phenyl-2/f,6/f-l,3-dioxin (124), as well as a mixture of acids... 

Further to investigate this similarity between nitrates and sulfonates, methyl 4,6-0-benzylidene-(and -alkylidene)-a-D-glucoside 2,3-dinitrates were treated with sodium methoxide in methanoP under the conditions used for converting the 2,3-ditosylates into the 2,3-anhydro-a-D-allosides. Much degradation occurred, even at 0°, and a large proportion of nitrite was formed. The only products isolated were the 2- and 3-nitrates of methyl... 

In a later investigation comparing the influence of different alkaline media, it was found that the methyl 3-keto-/3-n-glucoside (91 A) is degraded somewhat more slowly in sodium hydroxide (0.018 N, at 23°) than in lime-water of the same concentration. Further reaction of the dicarbonyl intermediate (112 B), to give acids, was much faster with lime-water, in accordance with the established catalyzing effect of calcium on saccharinic acid formation." ... 

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