Phenylalaninol (from phenylalanine) to amphetamine via red phosporus and iodine possible?

[Any7xxx]

ive always had times where i was tweaking so much from speed (from the way i write this you can probably see im tweaking rn ) that i couldnt stop to wonder about the possibilities of phenylalanine since it is so easy to get it and its chemical structure is so similar to amphetamin.
unfortunatly i barely passed middle school chemistry and since then have been too afraid to do anything chemistry related academicly so maybe my question is dumb.

one of the rhodium archives has a synthesis of amphetamine from phenylalanine which was shared in this forum aswell;
basicly you reduce dl-phenylalanine to dl-phenylalaninol via LAH -- simple enough (on paper :/)
but then getting rid of the -OH group in that synthesis is a lto harder. my question would be why cant you use the same method of getting rid of the -OH group as you do with ephedrine (via red phosfor and iodine)?

i couldnt find any mention of this in bbgate and even dread, despite not being particularly hard to think about so probably im missing something
here are the rhodium archives if anyone needs phe to amph 1 , phe to amph 2 (and meth)

 

[William D.]

This is a different substitution with a functional group, this case will not work like that.

 

[Eleusius_hive_reboot]

WHAT??? [ get schooled now, my dear Will ]

-----------------------------------------------------
PHENYLALANINOL-

(+)-2-Amino-3-phenylpropanol​

Hydroxyl >Sn2>subst.
I2 +P-red =
(triphenylphosphine,
in situ) ~leaving--group--->

***********************************************
REACTION MECHANICS
(nucleophilic substitution - Sn2
like the hypothesis this OP envisioned !!!
************************************************
anectdotal:
back in the Days, there was "the amphetamine-reduction-Contest"

at the Science-Madness Forum (maybe it was synthetikal. com, i dont remember exactly)

there was a one skilled User,, that successfully brought up this Route to yield
dextroamphetamine- he used an excess of reactants and reacted over a long period
(48hrs) - so technically it wasnt really worth it !!

But your claim is incorrect, in both ways ... its the same functional group AND reaction mechanics
are the same- only the drive towards the substitution is harder to achieve...!

 

[FQ-BB]