Reactions of C-terminal omega-amino acid residues in liquid hydrogen fluoride.
The benzyl-ester bond linking the C-terminal delta-aminovaleric acid residue of a peptide to a polymeric support was cleaved with liquid hydrogen fluoride in the presence of anisole, added as scavenger. Instead of the expected peptide with a free carboxyl group at the C-terminus, a peptide terminating in a ketone derivative was obtained. The unusual extent of this known side-reaction was attributed to the effect of the distance between the amino group and the carboxyl group in the C-terminal residue. The results of model experiments corroborated this view.
Bednarek
M A
MA
Merck Research Laboratories, Rahway, New Jersey.
Springer
J P
JP
Cunningham
B R
BR
Bernick
A M
AM
Bodanszky
M
M
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D006858:Hydrofluoric Acid; D007659:Ketones / Q000737:chemistry; D008722:Methods; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry
D000596:Amino Acids; D007659:Ketones; D009842:Oligopeptides; D006858:Hydrofluoric Acid