Question

Identify products A and B. $CH_3 - CH(CH_3) - CH_3 \xrightarrow{\text{dil. } KMnO_4, 273 K} A \xrightarrow{CrO_3} B$ 

• A. A
• B. B
• C. C
• D. D

Hint:

Tertiary carbons are the only alkane carbons easily oxidized by $KMnO_4$ to form alcohols.

Answer 1

The Correct Option is A

The given reaction involves two steps:

1. Oxidation with dilute KMnO₄:

   The compound given is CH_3-CH(CH_3)-CH_3 which is 2-methylpropane. When treated with dilute KMnO_4 in cold conditions (273 K), it undergoes oxidation. Alkynes and alkenes typically react with KMnO_4 to form diols. Here, the result will be a diol addition across the double bonds.

   The intermediate product, A, will be a diol with the structure:

   

2. Further oxidation with CrO₃:

   The compound A formed in the first reaction is further oxidized using CrO_3, which is a strong oxidizing agent. It will oxidize the secondary alcohol to a ketone.

   Thus, the product B will be a ketone with the structure:

   

Based on the given options, the correct answer is:

A

The structures of A and B are consistent with the given reaction sequence.