Fructose is obtained along with glucose by the hydrolysis of the disaccharide sucrose. It is a natural monosaccharide present in fruits, honey, and vegetables.

The existence of two crystalline forms (a and b) with different melting points (419 K and 423 K) cannot be explained by the open-chain structure (I). The proposal of a cyclic hemiacetal structure forming a six-membered ring, with —OH at ...

Glucose’s pentaacetate does not react with hydroxylamine, indicating the absence of a free —CHO group. This contradicts the open-chain structure (I) and suggests a different configuration.

Glucose does not react with Schiff’s test or form a hydrogensulphite addition product due to the absence of a free —CHO group. The open-chain structure (I) fails to explain these observations.

The lowest asymmetric carbon atom is considered for assigning the configuration of monosaccharides. In glucose, for example, the comparison is made based on the position of the -OH group on the lowest asymmetric carbon, comparing it to the corresponding position ...