Question

ii) Applying IUPAC rules, derive the structural formula of the following compounds.
a) Pentanoic acid
(b)2-methly-butan-2-ol
​

Answer 1

Answer:

a) CH3CH2CH2CH2COOH

b) CH3CH(CH3)CH2CH2OH

Answer 2

Answer:

The structural formula for

a) Pentanoic acid - CH₃-CH₂-CH₂-CH₂-COOH

(b)2-methyl-butan-2-ol - CH₃-C(CH₃)(OH)-CH₂-CH₃

Explanation:

The longest carbon chain is drawn(according to the root word)first to obtain the structure of an atom from the IUPAC name. Then number the carbon atoms. Now attach the different substituents at the mentioned places and satisfy the valencies of all the C atoms by putting the required number of hydrogen atoms.

a) Pentanoic acid

• Here, the root word is 'pent'. So, the principal chain has five C atoms.

• Give the number to the carbon.

• Attach the COOH group as the first carbon.

• Satisfy the valency of each carbon by adding the required number of hydrogen atoms.

The structure is shown below.

CH₃-CH₂-CH₂-CH₂-COOH

b) 2-methyl-butan-2-ol

• Here, 'but' is the root word, so the principal chain has four C atoms. Thus, draw a straight chain with four C atoms.
• Give the number to the carbon.
• Attach methyl group and -OH to the second carbon.
• Satisfy the valency of each carbon by adding the required number of hydrogen atoms.

The structure is

CH₃-C(CH₃)(OH)-CH₂-CH₃