Question

Wacker process is an industrial process for the oxidation of terminal alkenes. Which of the following represents a true statement about the product?
(This question has multiple correct options.)
(A) The product is an aldehyde with same number of carbon atoms as in alkene
(B) The product is a ketone with same number of carbon atoms as in the alkene
(C) The product is an oxirane with same number of carbon atoms as in the alkene
(D) The product is a terminal alcohol as the net reaction is hydration of alkene

Answer 1

Hint: This reaction oxidizes the more substituted carbon atom of the alkene. One of the products formed by this reaction will give positive Fehling’s test. Palladium chloride is used as a catalyst in this reaction.

Complete Step-by-Step Solution:
Wacker process oxidizes terminal alkenes in presence of Palladium and copper containing catalysts. Water is also needed in this reaction to get completed. This reaction involves formation of metal complexes, which react in order to give products.
Let’s see two examples to see which kind of products they will give.
$$C{H}_2=C{H}_2\underset{CuC{l}_2,O_2,H_{2}O}{\overset{PdC{l}_2}{\to }}C{H}_{3}CHO$$
$$C{H}_{3}CH=C{H}_2\underset{CuC{l}_2,O_2,H_{2}O}{\overset{PdC{l}_2}{\to }}C{H}_{3}COC{H}_3$$
We can see that Palladium chloride and Copper chloride are used as catalysts in both the reactions. Oxygen is used in order to regenerate the used catalysts. Water acts as a nucleophile and does attack on the alkene complex with metal to give an additional reaction.
So, we can see that we can obtain aldehydes as a product in this reaction that has the same number of carbon atoms as in the alkene. It can also give ketones as a product in which the total number of carbon atoms present in ketones and starting material alkene is the same.
- Oxirane is a group also called epoxide and it is not formed by the wacker process. The net reaction is not a hydration reaction of alkene, So, options (C) and (D) are not correct.

So, there are two correct options, (A) The product is an aldehyde with the same number of carbon atoms as in alkene and (B) The product is a ketone with the same number of carbon atoms as in the alkene.

Note: Remember that wacker process gives ketones as their exclusive products but do not forget the exception of ethylene as it contains the carbons such that both are primary only and so, it cannot form a ketone as it require minimum three carbons to be a ketone and so the resultant product will be aldehyde.