[addiemo]

Question 1.  Consider the information below regarding an unknown molecule X.
When Molecule X reacts with excess H2, Pd/C, 4 hydrogen atoms are added to the molecule.
When Molecule X reacts with excess H2, Lindlar’s catalyst, 2 hydrogen atoms are added to the molecule.
When Molecule X undergoes either hydroboration/oxidation or hydration, the same product is formed.
Which of the following structures could be molecule X?  Select all that apply.  the optinons are ethynylbenzene, 2-phenylethynylbenzene, trans-Piperylene, ethynylcyclopentane and 2,5-dimethylhexa-1,5-dien-3-yne. remember choose all that apply

I chose
Ethynylbenzene
2-Phenylethynylbenzene
Ethynylcyclopentane

I chose those because they meet the criteria of the reaction, however I got the problem wrong. Does anyone know why that might be and what would be correct, I am thinking that only one of them is incorrect as I am sure about ethynylbenzene but not 100% sure. Thank you.

[Babcock_Hall]

Try finding the products of each of your selections in hydroborations versus hydrations.