Reaktion #550045

ord-722f8b12187d4458918d4776aef8c308

Reaktionsgleichung

CC(C)(C)OC(=O)[C@@H](N)CC(N)=O
H-Asn-OtBu
CC(C)(C)OC(=O)CC[C@H](NC(=O)OCc1ccccc1)C(=O)O
Z-Glu(OtBu)-OH
→
CC(C)(C)OC(=O)CC[C@H](NC(=O)OCc1ccccc1)C(=O)N[C@@H](CC(N)=O)C(=O)OC(C)(C)C
Z-Glu(OtBu)-Asn-OtBu

Edukte

CC(C)(C)OC(=O)[C@@H](N)CC(N)=O
H-Asn-OtBu
—
anhydride
—
anhydride
CC(C)(C)OC(=O)CC[C@H](NC(=O)OCc1ccccc1)C(=O)O
Z-Glu(OtBu)-OH

Reagenzien

Keine

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    SonstigeFragment I was prepared by stepwise chain elongation
  2. 2
    Sonstigeat -15° C.

Vorschrift

Fragment I was prepared by stepwise chain elongation using the mixed anhydride procedure at -15° C. with careful temperature control. As seen in the scheme of FIG. 2 mixed anhydride (M.A.) coupling (isobutylchloroformate) of Z-Glu(OtBu)-OH with H-Asn-OtBu provided Z-Glu(OtBu)-Asn-OtBu. Catalytic hydrogenation (10% Pd-C) of this compound cleaved the N-terminal protective group and the dipeptide was coupled to Z-Ala-OH using mixed anhydride coupling to give Z-Ala-Glu (OtBu)-Asn-OtBu. The N-terminal was again deprotected by catalytic hydrogenation and the tripeptide coupled with Z-Glu(OtBu)-OH to give the protected tetrapeptide Z-Glu(OtBu)-Ala-Glu(OtBu)-Asn-OtBu which is deblocked by catalytic hydrogenation to provide the desired protected tetrapeptide (1).

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US04517119uspto-grants-1985_05