Question

Nitroalkane which do not exhibit tautomerism is:

• A. $3^o-$ nitroalkane
• B. $2^o-$ nitroalkane
• C. $1^o-$ nitroalkane
• D. all of these

Answer 1

Answer: (A)

Key Idea: Tautomerism arises due to presence of labile hydrogen in organic compounds. The compounds having $\alpha -$ hydrogen show tautomerism.
$\underset{1^{\circ }\text{nitroalkane}}{R-\underset{\stackrel{|}{H}}{\stackrel{\underset{|\alpha }{H}}{C}}-N{O}_2}\underset{2^{\circ }\text{nitroalkane}}{R-\underset{\stackrel{|}{H}}{\stackrel{\underset{|\alpha }{R}}{C}}-N{O}_2}\underset{3^{\circ }\text{nitroalkane}}{R-\underset{\stackrel{|}{R}}{\stackrel{\underset{|\alpha }{R}}{R}}-N{O}_2}$
$\because$ $3^o$ nitroalkane does not have any $\alpha -hydrogen$ atom.
$\because$ $3^o$ nitroalkane do not show tautomerism