(a) \(C - \overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}}-\overset{O}{\overset{||}{C}} - OH\)

OR \(CH_3-\overset{O}{\overset{||}{C}} - OH\)

(b) \(H - \overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}}- \overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} - Br \)

or CH₃ - CH₂ - CH₂ - CH₂ - CH₂ - Br

(c) \(H - \overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}}-\overset{O}{\overset{||}{C}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -H\)

Butanone

or \(H_3C-\overset{O}{\overset{||}{C}} -CH_2 - CH_3\)

(d) \(H - \overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}}- \overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}} -\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}}-\overset{O}{\overset{||}{C}}- H\)

Hexanal

or \(CH_3- CH_2 - CH_2 - CH_2 - CH_2-\overset{O}{\overset{||}{C}} -H\)

Bromopentane has a chain of five carbon atoms. It can exist in a number of forms which are structural isosmers.

(a) \(H_3- CH_2 - CH_2 - CH_2 - CH_2 -Br\)

1- bromopentane

(b) \(H_3C- CH_2 - CH_2 -\underset{Br}{\underset{|}{CH}} -CH_3\)

2- bromopentane

(c) \(H_3C- CH_2 - \underset{Br}{\underset{|}{CH}} -CH_2 - CH_3\)

3- bromopentane

(d) \(H_3C- \underset{CH_3}{\underset{|}{CH}} -CH_2 - CH_2 - Br\)

1-bromo-3-methylbutane

(e) \(H_3C-CH_2- \underset{CH_3}{\underset{|}{CH}} - CH_2 - Br\)

1-bromo-2-methylbutane

(f) \(C - \overset{CH_3}{\overset{|}{\underset{CH_3}{\underset{|}{C}}}}-CH_2 -Br\)

1-bromo-2,2-dimethylpropane

• The structural isomers (a), (b) and (c) which differ in the position of the Br atom are known as position isomers.
• The structural isomers (d), (e) and (f) which differ in the arrangement of carbon atoms in the chain are called chain isomers.
• In writing the IUPAC name, the prefix bromo is written before methyl. In fact, alphabetical order is followed while naming the different prefixes.