Structure elucidation and spectral assignment of analogs of navelbine® (8′‐noranhydrovinblastine)

During the development of the bis-indole alkaloid anticancer drug Navelbine® (vinorelbine), several chemical degradants of the drug were isolated and identified. These included 7′-nor-6′,9′-secovinorelbine (7′,8′-bisnor-6′,9′-secoanhydrovinblastine) and 4-deacetyl-8′-vinorelbine (4-deacetyl-8′-noranhydrovinblastine). The elucidation of the structure of 7′-nor-6′,9′-secovinorelbine is described; the assignment of the proton and carbon spectra of both compounds is contrasted to the shift assignments of Navelbine.