Here we're told to write a reaction of hydrogenolysis of Phenylalanine Benzoyl Ester. Right? So in this process, remember, we're using catalytic hydrogenation, which is just H₂ with our metal catalyst, in this case, palladium. We're going to cleave the CO bond here. And remember, what happens when we cut that bond, the oxygen gains an H to create an amino acid and the CH₂ gains an H, becoming a CH₃ group.

So what we're going to have here is we still have everything else here the same. Here's the carboxylic acid we just created, plus this CH₂ gains an H to become a CH₃, which is still connected to benzene. So we just created methylbenzene or toluene. So again, in this process, we're changing this beginning reactant into an amino acid plus toluene.