# Can a Lindlar catalyst reduce aldehydes, nitriles, and carbonitriles?

The major product obtained in the following reaction is:

Question source: JEE Main 2019

The molecule shown as product is the official answer given by JEE from the given options.

I have written the possible intermediate molecule formed by reagents. On Google I have obtained information in this PDF document (page 3) that a Lindlar catalyst is poisoned, so that it cannot reduce an aldehyde. Also there is no information of a Lindlar catalyst being used as the reducing agent for nitriles and carbonitriles.

So, is the answer by JEE incorrect or am I missing something?

• Note: $\ce{Pd/C}$ is not similar to $\ce{Pd/BaSO4}$ or $\ce{Pd/CaCO3}$. So the reagent in your question isn't Lindlar's catalyst in the first place. It behaves like normal $\ce{Pd/H2}$ as far as I've learnt.
– TRC
Aug 8 '21 at 5:10
• From MasterOrganicChemistry Reagent Guide - Pd/C reduces alkene, alkyne, nitro, cyanide, C=N, azide - and probably most other reducible groups too.
– TRC
Aug 8 '21 at 5:24
• From Organic Chemistry for JEE Advanced by KS Verma, Cengage publications - It reduces all of the above but they haven't mentioned alkyne and C=N. Most likely missed mentioning those two.
– TRC
Aug 8 '21 at 5:26
• Re "carbonitriles": Just "nitriles"? Aug 8 '21 at 14:55
• @PeterMortensen Essentially they are the same, but in some nomenclature rules, carbonitrile is used instead of nitrile: acdlabs.com/iupac/nomenclature/79/r79_566.htm Aug 9 '21 at 1:42

There is just a silly mistake. As TRC told, $$\ce{Pd/C}$$ is not a Lindlar catalyst and it behaves as a normal $$\ce{Pd/H2}$$. Refer to the link for more information.