Boc-phosphoamino acid derivatives with O-[di(4-nitrobenzyl)- or dicyclohexylphosphono]-protection were prepared for application to the Boc-mode solid-phase synthesis of phosphopeptides. These protecting groups are both stable to TFA, but removable with a combination of trifluoromethanesulfonic acid and methylthiobenzene in TFA. Of these derivatives, Nα-Boc-O-(dicyclohexylphosphono)serine and Nα-Boc-O-(dicyclohexylphosphono)threonine were obtained as crystalline compounds to be favorably utilized as starting materials for solid-phase synthesis using an automated peptide synthesizer. On the other hand, Nα-Boc-O-(dicyclohexylphosphono)tyrosine and all of the O-[di(4-nitrobenzyl)]phosphono derivatives were prepared as crystalline cyclohexylammonium or dicyclohexylammonium salts.
Peptidkonformationen, 40. Cyclische Hexapeptidanaloge des Thymopoietins Synthese und Konformationsstudien
作者:Horst Kessler、Bernhard Kutscher
DOI:10.1002/jlac.198619860509
日期:1986.5.13
cyclischen Hexapeptiden erbrachten unterschiedliche Ergebnisse. Für die beiden Glycin enthaltenden Cyclohexapeptide c1 und c2 muß aufgrund der NMR-spektroskopischen Daten ein Gleichgewicht mehrerer Konformationen angenommen werden. Dagegen sind die D- und L-Valin enthaltenden Cyclohexapeptide c3 und c4 konformativ einheitlich. Die Konformationsanalyse zeigt. daß diese Cyclopeptide in einer βII′βI′-Struktur vorliegen
tert-BUTOXYCARBONYLATION OF AMINO ACIDS AND THEIR DERIVATIVES: N-tert-BUTOXYCARBONYL-l-PHENYLALANINE
作者:Keller, Oskar、Keller, Walter E.、Van Look, Gert、Wersin, Gernot
DOI:10.15227/orgsyn.063.0160
日期:——
Polypeptides. LI. Application of S-ethylcarbamoylcysteine to the synthesis of a protected heptatetracontapeptide related to the primary sequence of ribonuclease T1
作者:Harold T. Storey、John Beacham、Stanley F. Cernosek、Frances M. Finn、Chizuko Yanaihara、Klaus Hofmann