Amino acids, the building blocks of
proteins, are one of the most interesting
biological molecules.
The Strecker Method
The
Strecker synthesis is a way to make amino acids from
aldehydes, and the
aldehyde used determines the amino acid which results.
Simply add to the aldehyde
ammonia, and remove the
water. To the resultant
imine (the
nitrogen of the
ammonia supplants the
oxygen of the
aldehyde), add
hydrogen cyanide. This will create an
amino nitrile. To this add
aqueous acid,
heat, and
water, and
voila, an
amino acid.
Organic Chemistry: Structure and Function by Vollhardt and Schore is the book my instructer taught us from, and it seemed to do a fine job of teaching this
chemistry and the rest of organic chemistry that one learns as an undergraduate.
Amino acids are the
building blocks of
proteins. The following is one of several ways to
synthesize amino acids. Its advantage over some other ways is the wide
variety of amino acids which can be synthesized in this
fashion.
The first step is to take
potassium 1,2-
benzene-
dicarboxylic
imide and add to it
diethyl 2-
bromo-
propanedioate. The result is that the
nitrogen of the prior
reagent, which has a full
negative charge, attacks the
carbon which the
bromine is attached to on the second
reagent, kicking off said
bromine.
At this point, one can replace the
hydrogen on this
carbon with a different
side chain (this is where the variety I mentioned earlier is possible). Simply add
sodium ethoxide and
ethanol to de
protonate the carbon, and add your side chain attached to a
halogen (
chlorine,
bromine, &c.).
Finally, heat it up in the presence of
aqueous acid to clear out the
protecting group (what the 1,2-benzene-dicarboxylic imide turned into).
The Gabriel Synthesis
The advantage of the Gabriel synthesis over some other ways is the wide
variety of amino acids which can be synthesized in this
fashion.
The first step is to take
potassium 1,2-
benzene-
dicarboxylic
imide and add to it
diethyl 2-
bromo-
propanedioate. The result is that the
nitrogen of the prior
reagent, which has a full
negative charge, attacks the
carbon which the
bromine is attached to on the second
reagent, kicking off said
bromine.
At this point, one can replace the
hydrogen on this
carbon with a different
side chain (this is where the variety I mentioned earlier is possible). Simply add
sodium ethoxide and
ethanol to de
protonate the carbon, and add your side chain attached to a
halogen (
chlorine,
bromine, &c.).
Finally, heat it up in the presence of
aqueous acid to clear out the
protecting group (what the 1,2-benzene-dicarboxylic imide turned into).
An excellent explanation of thess and other amino acid syntheses can be found in
Organic Chemistry: Structure and Function by
Vollhardt and
Schore.