Question

The aromas of many flowers and fruits are due to esters such as those shown in this problem. What are the common names of these esters? (Also see Problem 57.)

Short answer

(a)Benzyl acetate

(b)Isopentyl acetate

(c) Methyl butyrate

Step-by-step solution

Esters

Esters are carboxylic acid derivatives in which OH group is replaced by OR^’group.

They have two alkyl groups: one is attached to carbonyl group and other to carboxyl oxygen.

 Naming of ester

The group attached to carboxyl oxygen is stated first then is followed by parent chain name and at end instead of ‘ic acid’, ‘ate’ is used.

Common name of (a) jasmine aroma ester

(a)

Here methyl group is present on phenyl groupwhicht is known as benzyl group. As it is discussed above, first write group attached to carboxyl oxygen and then carbonyl one with ‘ate’ at the end of name.

Acetyl is used in common names for group. The common name of this compound is Benzyl acetate

 Step 4: Common name of (b) banana aroma ester

(b)

As here, five carbon chain with iso- configuration present attached to carboxyl oxygen so this group is called isopentyl. The other group is acetyl group and as mentioned earlier for ester at the end ‘ate’ is used.

The common name of this compound is Isopentyl acetate.

Common name of (c) apple aroma ester

(c)

As here, only one carbon is present attached to carboxyl oxygen so this group is called methyl. The other group has four carbon including carbonyl carbon so it is butyl and as mentioned earlier for ester at the end ‘ate’ is used.

The common name of this compound is methyl butyrate.