Reacción #550045

ord-722f8b12187d4458918d4776aef8c308

Condiciones de reacción

Condiciones detalladas
See reaction.notes.procedure_details.

Tratamiento posterior

  1. 1
    OtroFragment I was prepared by stepwise chain elongation
  2. 2
    Otroat -15° C.

Procedimiento

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).

Fuente

DOI: 10.6084/m9.figshare.5104873.v1Patente: US04517119uspto-grants-1985_05