Assessment of racemisation in N-alkylated amino-acid derivatives during peptide coupling in a model dipeptide system
- 1 January 1981
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- No. 11,p. 2982-2990
- https://doi.org/10.1039/p19810002982
Abstract
N.m.r. analysis of diastereoisomeric benzoyl dipeptide esters has been used to monitor racemisation during the coupling of benzoyl-N-alkylated amino-acids to alanine and valine methyl esters. Results confirm the greater susceptibility of these amino-acids to racemisation, but conditions have been found which eliminate racemisation. The additives HONSu and HOBt vary in their capability as ‘chiral stabilisers’. N.m.r. techniques provide a facile means for monitoring the involvement of oxazolonium ions during coupling. A possible mechanism for racemisation is proposed.This publication has 5 references indexed in Scilit:
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