[NO2]

Hi
The synthesis of homocysteine is what I'm not capable of.
In the human body it comes from methionine  http://en.wikipedia.org/wiki/Methionine#Generation_of_homocysteine

How would I go about this in a lab?
Thanks a lot.

[Babcock_Hall]

I have occasionally purchased this material commercially and was not overly impressed with its purity.  I once found an interesting synthesis of homoserine (via dipolar addition chemistry IIRC), and I wondered whether it would be possible to make homocysteine in a similar way.  I never followed up on it, however.  Why do you want to make it?

[NO2]

Hi
I've read that the synthesis of homocysteine is known to those "knowledgeable in the art" or something like that. I need it for a research project, and the costs of a larger amount (1 g) are just to steep, due to the scarcity of its use.

[kriggy]

I would go for Strecker synthesis with 3-mercaptopropanal or with chloro/bromo propanal which is cheaper and allows you to convert the halohen group into mercpato group.

[Babcock_Hall]

2-tert-Butyl-3-methyl-2,3-dihydroimidazol-4-one-N-oxide: A New Nitrone-Based Chiral Glycine Equivalent
Steven W. Baldwin* and Alan Long, Org. Lett., Vol. 6, No. 10, 2004

The authors made derivatives of homoserine.  I have no idea whether or not the chemistry could be adapted to derivatives of homocysteine.

[NO2]

Thanks a lot for the posts! I'm wondering, based in the fillowing information, if one could just demethylate methionine to get homocystine.
n more detail: in the Methionine Cycle, methionine's methyl group becomes activated by ATP (adenosine triphosphate) with the addition of adenosine to the sulfur of methionine, adjacent to the methyl group to form S−Adenosyl Methionine (SAMe). Removal of the methyl group from SAMe results in the formation of S−Adenosyl Homocysteine (SAH), which is immediately converted to the amino acid homocysteine by removal of the adenosine molecule

[NO2]

So, I find out how it used to be done:
http://www.jbc.org/content/99/1/135.full.pdf
heat methionine with sulferic acid (N18 which is ca. 52%) 125-135 Celsius to create (42.5% of methionone) homocystine.
If you need homocysteine, sodium metal and liquid ammonia should do the trick (Reductive cleavage of L-homocystine with sodium in liquid ammonia produced homocysteine).


Now all I need to know is how to make  2-(N-benzyloxycarbonyl-amino)ethyl tosylate , but I'll ask on this thread:http://www.chemicalforums.com/index.php?topic=74927.0