Esters of Carbohydrates Mono- and Disaccharides

The Pd(Ph3P)4-catalyzed removal of the 0-allyl protecting group has been described for a number of systems. For example, allyl esters are efficiently cleaved to the parent acid in chemically sensitive systems such as penicillins and glycopeptides. The internucleotide phosphate linkage, protected as the allyl phos-pho(III)triester, remains intact upon deprotection under Pd(Ph3P)4 catalysis. Allyl ethers that protect the anomeric hydroxy in carbohydrates (mono- and disaccharides) are efficiently removed under Pd(Ph3P)4 catalysis in hot (80 °C) HOAc. ... 

Even isolated mono- and disaccharides are capable of extensive hydrogen bonding, which results in extremely low vapor pressures. Attempts at vaporization of these materials results in decomposition. Volatile derivatives must be prepared and the approaches are similar to those described for amino acids. The most common derivatives are methyl or trimethylsilyl ethers and acetyl or trifluoroacetyl esters. A highly detailed review of applications of GLC to carbohydrates including over 1000 references concerning derivatization and types of columns used has been written by Dutton (69,70). 

ASs are able to hydrolyze a variety of sulfate esters. Depending on the enzyme specificity the physiological substrates include, among others, small mono- and disaccharide sulfates, hydrophobic steroids, and amphiphilic sulfated carbohydrates found in glycosaminoglycans (GAGs). However, small synthetic aryl sulfates are the... 

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