Monosaccharides Kiliani-Fischer reaction

Show the common reactions of monosaccharides that were presented in this chapter oxidation with nitric acid oxidation with bromine reduction with sodium borohydride esterification glycoside formation and the Kiliani-Fischer synthesis. 

Kiliani-Fischer synthesis (p. 1139) Lobry de Bruijn-Alberda van Ekenstein reaction (p. 1141) monosaccharide (p. 1161)... 

The Kiliani—Fischer synthesis extends chains of monosaccharides using the formation of a cyanohydrin to generate the additional stereogenic center. In the first step, one enantiomeric form of an aldose reacts with HCN to give a mixture of diastereomeric cyanohydrins. We recall that the formation of an additional stereogenic center in a chiral compound results in some stereoselectivity. A mixture results, but because diastereomers have different physical properties, the reaction mixture can be separated to give two cyanohydrins. 

The Ruff degradation and the Wohl degradation both cleave the carbonyl-bearing carbon from a monosaccharide to form a new monosaccharide of one fewer carbon. The Nef reaction adds one carbon to a monosaccharide to form a new monosaccharide, as does the Fischer-Kiliani synthesis. 

In many cases the homologation steps represented by arrows on page Cl have been realised in practice, by sequences such as R-CHO - RCH(OH)CN - RCH(OH)CHO (Fischer-Kiliani reaction) but even in cases where they have not, the configurations of the individual monosaccharides are supported by a wealth of other evidence [ 1 ] [2]. 

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