Preparation of an aspartic acid-containing protected peptide. Alternatives for overcoming a side reaction during HF treatment.
Treatment of the peptide-resin Ac-Asn-Ser(Bzl)-Gly-Asp(OFm)-pMeBHA with HF/anisole cleaves the peptide-resin bond and removes the benzyl group, as expected, but also yields an impurity (ca. 25%) in which the benzyl group is linked to the fluorenylmethyl protecting group. Separation of the desired peptide from the impurity can be accomplished by reversed-phase medium-pressure liquid chromatography. The side reaction does not take place when the gamma-carboxyl of aspartic acid is protected with the 2-(4-acetyl-2-nitrophenyl)ethyl group.
Robles
J
J
Department of Organic Chemistry, Faculty of Chemistry, University of Barcelona, Spain.
Pedroso
E
E
Grandas
A
A
D000478:Alkylation; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D000840:Anisoles / Q000494:pharmacology; D001224:Aspartic Acid; D005449:Fluorenes / Q000737:chemistry; D006858:Hydrofluoric Acid / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000302:isolation & purification
D000596:Amino Acids; D000840:Anisoles; D005449:Fluorenes; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D009842:Oligopeptides; D001224:Aspartic Acid; C060998:anisole; D006858:Hydrofluoric Acid