D-(+)- Glucose xrightarrow5(CH3CO)2OD-(+)- Glucose pentaacetate Which statement(s) is/are true about glucose pentaacetate?

Question

D-(+)- Glucose xrightarrow5(CH3CO)2OD-(+)- Glucose pentaacetate Which statement(s) is/are true about glucose pentaacetate? (A) It will react with phenylhydrazine but not with Tollens’ reagent (B) It will react with Tollens’ reagent but not with phenylhydrazine (C) It will react with both of the above mentioned reagents (D) It will react neither with phenylhydrazine nor with Tollens’ reagent

Tardigrade Admin · Accepted Answer

During acetylation of (+)-glucose, it is the C1 - OH of the hemiacetal that is acetylated and not the C5-OH that forms the ring (cyclic structure). Since equilibrium with the open-chain aldehyde is prevented, the pentaacetate does not respond to the aldehydic reactions.

Q. $D - (+) -$ Glucose $5 (C H_{3} CO)_{2} O D - (+) -$ Glucose pentaacetate
Which statement(s) is/are true about glucose pentaacetate?

It will react with phenylhydrazine but not with Tollens’ reagent

It will react with Tollens’ reagent but not with phenylhydrazine

It will react with both of the above mentioned reagents

It will react neither with phenylhydrazine nor with Tollens’ reagent

During acetylation of (+)-glucose, it is the $C_{1} - O H$ of the hemiacetal that is acetylated and not the $C_{5} - O H$ that forms the ring (cyclic structure). Since equilibrium with the open-chain aldehyde is prevented, the pentaacetate does not respond to the aldehydic reactions.

Q. D−(+)− Glucose 5(CH3​CO)2​O​D−(+)− Glucose pentaacetate Which statement(s) is/are true about glucose pentaacetate?