Dakin-West Reaction on Phenylalanine the Amino Acid
I have a reaction that requires the removal of the CH3 from a ketone ,but first in a Dakin -West reaction the amino acid Phenylalanine is treated
with acetic anhydride will make an ozaxolone, meaning a ketone where the carboxylic acid active group formerly resided and an amide where the amine
group formerly resided. The task is to remove the CH3 to leave the alkane and the amide in place, later the amide can be reduced to a methylamine .
Here are some facts regarding Dakin-West reaction and how it can be applied to our Phenylalanine. "When an amino acid is treated with an
anhydride in the presence of pyridine, the carboxyl group is replaced by an acyl group and the NH2 becomes acylated. This is called the Dakin-West
reaction. The mechanism involves formationof an oxazolone. The reaction sometimes takes place on carboxyl acids even when an amino group is not
present . A number of N-substituded amino acids , RCH(NHR' )COOH, give the corresponding N_alkylated products. " as stated on page 812 from
5th edition March's text.
Ref.
for a review, see Buchanan, G.L.Chem.Soc.Rev.,1988,17,91 Allinger, N.L.; Wang, G.L. ; Dewhyrst, B.B., Org. Chem., 1974,39,1730
Note:
...........pyridine can be substituded with sodium acetate or alkylpyradines,
Now here is an idea for removel of the CH3......March's 5th ed. page 318, .....through some photochemistry ketones can be processed through type
I cleavage in the Norrish Type I cleavage
HV
R'-CO-R -------> R'-CO- + R
hence , need to find type of conditions and methods for this Norrish type I cleavage....any suggestions........solo
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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