KCET2014ChemistryChemistry in Everyday Life
The statement that is NOT correct is
Options
- ACarbohydrates are optically active,
- BLactose has glycosidic linkage between ( C₄ ) of glucose and ( C₁ ) of galactose unit.
- CAldose or ketose sugars in alkaline medium do not isomerism.
- DPentaacetate of glucose does not react with hydroxylamine.
Correct answer
C. Aldose or ketose sugars in alkaline medium do not isomerism.
Step-by-step solution
Aldose or ketose sugars in alkaline medium isomerize. For example; on heating with conc. solution of ( NaOH ) glucose (aldose) first turns yellow and then brown and finally resinifies with dilute solution of ( NaOH ) glucose (aldose) undergoes a reversible isomerization and is converted into a mixture of D-glucose, D-maltose and D-fructose. This reaction is known as lobry de Bruyn-van Ekenstein rearrangement.