NEETChemistryAldehydes and Ketones
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): 2,2 -Dimethylpropanoic acid does not give the Hell-Volhard-Zelinsky (HVZ) reaction. Reason (R): The HVZ reaction requires the presence of at least one -hydrogen atom in the carboxylic acid, which 2,2 -dimethylpropanoic acid lacks. In the light of the above statements, choose the most appropriate an
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
The Hell-Volhard-Zelinsky (HVZ) reaction involves the halogenation of carboxylic acids at the -position. This reaction specifically requires the presence of at least one -hydrogen atom in the carboxylic acid molecule. The structure of 2,2 -dimethylpropanoic acid (also known as pivalic acid) is (CH₃)₃C-COOH . The -carbon (the carbon atom adjacent to the carboxyl group) is bonded to three methyl groups and has no hydrogen atoms attached to it. Since it lacks an -hydrogen, it cannot undergo the HVZ reaction. Therefore