What is the major product of the following reaction?

Question

Quizplus · Accepted Answer

In the given reaction, the alkene undergoes a catalytic hydrogenation reaction in the presence of platinum on carbon (Pt/C) to form the corresponding alkane. The cis isomer of the alkene in Option II (2-butene) can only produce one product upon hydrogenation as it has a plane of symmetry and thus gives a meso compound. The trans isomer in Option I (2-butene) can produce two products, one with both hydrogens on the same side (cis) and one with the hydrogens on opposite sides (trans). Option III (3-hexene) can produce only one product upon hydrogenation as there is only one possible arrangement of hydrogens. Option IV (1,3-butadiene) can produce two products upon hydrogenation; however, one product will have both carbons with a hydrogen, and the other product will have two carbons with a double bond between them. Thus, the major product of the given reaction will be the alkane formed from the hydrogenation of the trans isomer of 2-butene (Option I) and the cis isomer of 2-butene (Option II) as they each can produce only one product. Therefore, the correct answer is B, only I and IV.

What Is the Major Product of the Following Reaction