Monosaccharides, chiral analysis

Aldonolactones are useful starting materials for the synthesis of modified sugars. They have also been used as chiral templates in synthesis of natural products. Some of them are inexpensive, commercially available products or they may be obtained readily from the respective monosaccharides. The purpose of this chapter is to survey the main reactions of aldonolactones. Previous reviews on the subject include articles on gulono-1,4-lactones (1) and D-ribonolactone (2). Methods of synthesis, conformational analysis, and biological properties are not discussed in this chapter. 

The introduction of g.l.c. for oligosaccharide analysis constituted a major breakthrough in the field. In addition to strategies for accurate and sensitive quantitation of monosaccharide type (19,20), chiral procedures may be adopted for enantiomeric (d and l) determination (21). The sensitivity of h.p.a.e. chromatography with pulsed amperometric detection now provides an alternative to g.l.c. for oligosaccharide compositional analysis (22). 

H-NMR studies and analysis of sensor responses in the CD spectrum - after addition of sugar as guest to the dendrocleft host - show that the ability of this dendritic host to enantioselectively recognise monosaccharides decreases with increasing generation number of the dendron surrounding the chiral core unit. 

The absolute configuration of the monosaccharides can be determined by analyzing the sugars (obtained from hydrolysis experiments) on a chiral HPLC column (86, 87). The absolute stereochemistry of the monosaccharides may also be derived by chiral GC analysis (88, 89). Moreover, one can also compare the observed value of the molecular rotation with the value calculated on the basis of Klyne s rule (90). 

---