Monosaccharides methylated, quantitation

A novel synthesis of branched-chain monosaccharides was based on the finding that 3-furoic acid readily undergoes Birch reduction, affording 2,3-dihydro-3-furoic acid. Treatment of its methyl ester 398 with methanol and acid gave,264 in quantitative yield, methyl tetrahy-dro-5-methoxy-3-furoate 399 as a mixture of the isomers. Compounds... 

The use of gas chromatography requires volatile compounds, of course, and derivatives must be made of the hydrolyzed monosaccharides. Many investigators have used methylation or acetylation to produce these derivatives (10,16). However, both of these methods require more steps than are desirable with a small sample. In addition, the reaction time required for quantitative conversion to the derivative may be a problem. The use of trimethylsilyl ethers makes the derivatization exceedingly simple and relatively fast. Formation of these derivatives in the absence of water has been shown to occur without anomerization and to proceed quantitatively (30,31). The reaction mixture is chromatographed directly (Figure 9). 

Honda et al. [142] reported that l-phenyl-3-methyl-5-pyrazolone reacted with reducing carbohydrates aintost quantitatively to yield strongly UV-absorbing derivatives. This reaction differs from other derivatization reactions via the hydroxy group of carbohydrates, such as benzoylation or, p-bromobenzoylation, in that it gives no stereoisomers. This method is especially useful for the analysis of component monosaccharides of gly-... 

Zanetta J-P, Timmerman P, and Leroy Y (1999a) Gas-liquid chromatography of heptafluorobutyrate derivatives of the O-methyl glycosides on capillary columns a method for the quantitative determination of the monosaccharide composition of glycoproteins and glycoli-pids. Glycobiology 9 255-266. 

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