ISSN:
1573-3904
Keywords:
coupling reagents
;
HATU
;
hindered amino acids
;
solid phase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The difficulty during SPPS in acylating thesecondary amino group of Htc, a locally constrainedtyrosine, can be correlated with the steric hindranceof the amino acid or with the conformation of the growingpeptide chain. Our experimental data indicate that theavailability of the Htc amino group is associated with itssteric hindrance rather than a conformational effectof the peptide chain.An optimized solid phase automated protocol for Htcis reported. Under optimal conditions, Fmoc-aminoacids with hindered side chains were incorporated inapproximately 99% yield using HATU as couplingreagent. Unhindered side chain amino acid acylated thesecondary amino group of Htc in good yield underclassical HBTU/HOBt coupling conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008912426423