Bond_DoubleBond (Hive Bee)
05-23-04 15:51
No 508998
       OCl- oxidation of 3,4-methylenedioxy-phenylalanine     

After some searching, swim has found that an OCl- oxidation of phenylalanine results in the aldehyde, and 3,4-methoxy-phenylalanine results in the 2-ketone.  Would an OCl- oxidation on 3,4-methylenedioxy-phenylalanine result in the ketone as well? 		 
 
 
 
    Aurelius
(Active Asperger Archivist)
05-23-04 18:08
No 509025
       NO     

if you did a search, you would have found the post regarding this question.
answer
Post 476895 (josef_k: "You will not get P2P from hypochlorite ...", Stimulants)
Post 108379 (dormouse: "acetaldehyde + CH3MgBr -> Pol.  -Piglet", Novel Discourse)
shows MD-Ph-Ala and Ph-Ala degradation with OCl-
Post 303321 (kurupira: "found ref.!", Serious Chemistry)

procedure
Post 476937 (Lucid_Dreamer: "1b) (alternative) JACS 70, 3868 (1948) Distill", Stimulants)

(search terms: hypochlorite, phenylalanine)shocked
Act quickly or not at all. 		 
 
 
 
    Rhodium
(Chief Bee)
05-23-04 22:37
No 509085
       Incorrect starting material     

I believe that Mr. Bond is mistaken about 3,4-dimethoxyphenylalanine turning to the corresponding phenylacetone upon hypochlorite oxidation. The reaction is called "strecker degradation" and will turn any phenylalanine to its corresponding phenylacetaldehyde.

For the end product to be a phenylacetone, the starting material needs to be an alpha-methyl-phenylalanine.

Strecker Degradation of alpha-Methyl-3,4-dimethoxyphenylalanine to 3,4-dimethoxyphenylacetone (../rhodium /p2p.strecker.html)
The Hive - Clandestine Chemists Without Borders 		 
 
 
 
    mellow
(Hive Bee)
05-24-04 12:40
No 509214
       C-alkylate instead     

I agree with Rhodium.

But if one had 3,4-methylenedioxy-phenylalanine wouldn't it be a good idea to alkylate with a methyl group at the alpha position followed by the nitrogen, decarboxylating along the way.
1) R1-CH2-CH(NH2)-COOH + EtOH  --> R1-CH2-CH(NH2)-CO.OEt (Fisher esterification, refux with 5% HCl added via gassing)
2) R1-CH2-CH(NH2)-CO.OEt + R2-CHO  -->  R1-CH2-CH(N=CH-R2)-CO.OEt
3) R1-CH2-CH(N=CH-R2)-CO.OEt + MeX  -->  R1-CH2-C(Me)(N=CH-R2)-CO.OEt  [strong basic conditions with a PTC]
4) R1-CH2-C(Me)(N=CH-R2)-CO.OEt  --> R1-CH2-C(Me)(NH2)-CO.OEt  [hydrolysis]
5) R1-CH2-C(Me)(NH2)-CO.OEt  -->  R1-CH2-C(Me)(NH2)-COOH  [hydrolysis]
6) R1-CH2-C(Me)(NH2)-COOH - CO2 -->  MDA  [decarboxylation]

R1 : 3,4-MD-phenyl-
R2 : substituted-phenyl-  [eg. para-chloro-phenyl]
X : halogen (bromide / iodide)
Me : Methyl-
Et : Ethyl-

I appreciate that it looks like a large number of reactions but these are all very high yield and quite simple.  It's an easier and higher yielding route than what you propose, which anyway, wouldn't work as you plan.