Question

The correct representation of 4- hydroxy- 2-methylpent-2-en-1-al is :

• A. ${CH}_3-\underset{\stackrel{|}{OH}}{CH}-CH=\underset{\stackrel{|}{{CH}_3}}{C}-CHO$
• B. ${CH}_3-\underset{\stackrel{|}{{CH}_3}}{CH}-CH=\underset{\stackrel{|}{OH}}{C}-CHO$
• C. ${CH}_3-\underset{\stackrel{|}{{CH}_3}}{\stackrel{\underset{|}{{CH}_3}}{C}}-CH=\underset{\stackrel{|}{{CH}_3}}{C}-CHO$
• D. ${CH}_3-\underset{\stackrel{|}{OH}}{CH}-{CH}_2-\underset{\stackrel{|}{{CH}_3}}{CH}-CHO$

Answer 1

The correct option is A ${CH}_3-\underset{\stackrel{|}{OH}}{CH}-CH=\underset{\stackrel{|}{{CH}_3}}{C}-CHO$

$C{H}_3-\underset{OH}{\underset{|}{C}H}-CH=\underset{C{H}_3}{\underset{|}{C}-}CHO$

Numbering of parent chain will occur from right hand side because $f^n$ group like aldehyde is given lowest numbering.

$\stackrel{5}{C}{H}_3-\underset{OH}{\underset{|}{\stackrel{4}{C}}H}-\stackrel{3}{C}H=\underset{C{H}_3}{\underset{|}{\stackrel{2}{C}}-}\stackrel{1}{C}HO$

4-hydroxy-2-methylpent-2-en-1-al