Question

Give the product expected when the following alcohol reacts with pyridinium chlorochromate (PCC).

(Assume that PCC is present in excess.)

Answer 1

Concept and reason

The concept used is to predict a carbonyl compound's formation by the reaction between alcohol and excess pyridinium chloride. Pyridinium chloride is an oxidizing agent that oxidizes the alcohol group into the 1carbonyl group.

Fundamentals

The \(-\mathrm{OH}\) group in the reactant will decide the carbonyl compound formed in the reaction. \(1^{\circ}-\mathrm{OH}\) are oxidized to aldehydes by PCC. \(2^{\circ}-\mathrm{OH}\) are oxidized to ketones by \(\mathrm{PCC}\) \(3^{\circ}-\mathrm{OH}\) produce no reaction by the oxidation of \(\mathrm{PCC} .\) Reaction of alcohols with PCC forms a carbonyl compound.

 

Consider the given reactant as follows:

Here in this reactant, there are two \(-\mathrm{OH}\) groups. The reaction is as follows:

The \(1^{\circ}-\mathrm{OH}\) alcohol group that is present on the ethyl substituent is oxidized to the aldehyde group. [Hint for the next step] Identify the product of the reaction by the oxidation of \(3^{\circ}-\mathrm{OH}\) group.

 

The reaction is as follows:

Part 1 Therefore, the product of the reaction is as follows:

The \(-\mathrm{OH}\) group that is directly attached to the cyclobutane ring is a \(3^{\circ}-\mathrm{OH}\) group. Although excess \(\mathrm{PCC}\) is present, there is no reaction on this \(3^{\circ}-\mathrm{OH}\) group.