ISSN:
1573-3904
Keywords:
coupling reagents
;
HATU
;
hindered amino acids
;
solid phase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary The difficulty during SPPS in acylating the secondary amino group of Htc, a locally constrained tyrosine, can be correlated with the steric hindrance of the amino acid or with the conformation of the growing peptide chain. Our experimental data indicate that the availability of the Htc amino group is associated with its steric hindrance rather than a conformational effect of the peptide chain. An optimized solid phase automated protocol for Htc is reported. Under optimal conditions, Fmoc-amino acids with hindered side chains were incorporated in approximately 99% yield using HATU as coupling reagent. Unhindered side chain amino acid acylated the secondary amino group of Htc in good yield under classical HBTU/HOBt coupling conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02443565