Chapter 16, Problem 61P

Interpretation Introduction

(a)

Interpretation:

The hemiacetal in glucosamine should be labeled.

Concept Introduction:

The addition of one molecule of alcohol to an aldehyde or ketone results in a hemiacetal. Here, the C=O double bond breaks and single bonds are formed. If the hemiacetal is acyclic, it is not stable. Acyclic hemiacetal reacts with a second alcohol molecule and forms acetal.

Interpretation Introduction

(b)

Interpretation:

All the functional groups in glucosamine should be labeled.

Concept Introduction:

The addition of one molecule of alcohol to an aldehyde or ketone results in a hemiacetal. Here, the C=O double bond breaks and single bonds are formed. If the hemiacetal is acyclic, it is not stable. Acyclic hemiacetal reacts with a second alcohol molecule and forms acetal.

Even though acetals contain C-O-R bond, acetals are not ethers. Acetals have 2 OR groups attached to a single C atom. But an ether has one O atom which is bonded to 2 carbons.

Alcohols are compounds which have OH groups.