we have to develop analytical methods for process control of a lengthy organic synthesis. In one step N-BOC protected amino acids (i.e. amino acids with a BOC [= tert butyloxy carbonyl] group attached to the amino group) were produced. We should control the enantiomeric excess in this step without (!) removing of the BOC-group. Therefore we are looking for methods for the enantiomeric separation of BOC-protected amino acids. We believe that GC is the best choice, however, we donīt know methods for the derivatisation of the carboxyl group that (1.) do not remove the BOC-group and (2.) enables us to use commercially available phases (Chirasil-Val, Cyclodextrin phases etc.). Does anyone has experience with the enantiomeric separation of BOC-protected amino acids via GC, especially for proline derivatives?
Thanks a lot in advance!
By Anonymous on Sunday, June 9, 2002 - 06:32 pm:
Try emailing Alberta Peptide Institute,
they have lots of experience with boc-as well as fmoc amino acids
By Benjamin on Monday, June 10, 2002 - 05:18 am:
HPLC could be a better answer for your problem. Most likely there is enough information in the literature to give you an idea of the columns and conditions required to separate your enantiomers (without derivatization).
Please consult one of my publications: Chiral HPLC separation of protected Amino Acids", J. Liq. Chrom & Rel. technol. 21 (6), 777-791 (1998).
By Anonymous on Tuesday, June 11, 2002 - 05:09 am:
t-BOC protected amino acids are VERY temperature sensitive. The bond will break at relatively low temperatures (80-100°C) and are sensitive to the presence of water. You really need to do a literature search unless someone on the forum has the information at hand, although it might be proprietary and thus not available for public disclosure.
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