Question

Axial alcohols are oxidized faster than equatorial alcohols by PCC and other oxidants. Which OH group in each compound is oxidized faster?

a.

b.

Short answer

Answer

a.

b.

Step-by-step solution

Alcohols

Alcohols can be generated using alkanes, alkyl halides, and carbonyl compounds. Incorporating a Grignard reagent into a carbonyl compound in the presence of ether and ${\mathbf{H}}_{\mathbf{3}}{\mathbf{O}}^{\mathbf{+}}$ creates alcohol.

Oxidation of alcohols

Alcohol can be transformed into a carboxylic acid, and this reaction constitutes a principal part of organic chemistry. The oxidants employed in this process include Jones reagent, potassium dichromate, etc. A mild oxidizing agent like PCC is used to transform alcohols into aldehydes.

Identification of the OH group that gets oxidized faster

a. The structure of compound A can be given as:

Structure of compound A

Axial hydrogens are oxidized faster than equatorial hydrogens. The three-dimensional structure of compound A can be given as:

Three-dimensional structure of compound A

Hence, the OH group present at the axial part is oxidized faster than the one present at the equatorial region.

b. The structure of compound B can be given as:

Structure of compound B

Axial hydrogens are oxidized more quickly than equatorial hydrogens. The OH group in compound B that gets oxidized faster is found at the axial position. The three-dimensional structure can be given as:

Three-dimensional structure of compound B