D-Glucuronic acid methyl ester

S). Upon acetylation and esterification, the natural product gives a tri-0-acetyl methyl ester. This product is identical with that obtained by the reaction of 1-bromotetra-O-acetyl-D-glucuronic acid methyl ester with silver benzoate and must have the 0-benzoyl group at carbon 1. 

A series of derivatives analogous to those from D-glucuronic acid has been made by Morell and Link.68 An important compound is the crystalline methyl ester of methyl a-D-galacturonoside (XXXII) which on alkaline hydrolysis yields methyl a-D-galacturonoside (XXXIII). Since... 

Figure 3.8(a) Possible ester linkage between an a-OH of lignin and a carboxyl group of a 4-0-methyl-/3-d-glucuronic acid residue on the xylan backbone. 

A. F. Bochkov and Ya. V. Voznyi, Sugar ortho esters. Part 8. Synthesis of 4-O-methyl-D-glucuronic acid derivatives, Carbohydr. Res., 32 (1974) 1-8. 

SCHEME 3.9 Formation of the methyl ester of D-glucuronic acid. 

As previously mentioned, the methyl donor " for the formation of 4-O-methyl-D-glucuronic acid of hemicellulose B proved to be S-adenosyl-L-methionine, as in the formation of the methyl ester of pectin. ... 

O. 3 0.6 0.5, respectively, as well as 2,4-di-O-methyl-D-galactose. Each polysaccharide contained, in addition, 10% half-ester sulphate and ca. 0.5% protein. Structural studies showed, inter alia, that the D-glucuronic acid residues were linked to 0-3 of the D-galactose residues and that 2-0-methyl-D-glucuronic acid residues were linked to 0-4 of the L-galactose residues. The polysaccharide from... 

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