im trying to make it myself this is why i'm asking
I understand but you are going to start with phenylalanine, attempt to covert via benzaldehyde to a crude mixture of benzoic acid and benzylalcohol, then slectively oxidise the alcohol to the aldehyde or selectively reduce the acid to the aldehyde.
First of all I am not convinced that this reaction would work in the first place. I can't see a rational mechanism for this to happen.
So why not skip the dubious step one and purchase some benzoic acid and make benzaldehyde from that?
There are many routes to making benzaldehyde, why not investigate an alternative precursor?