(1S,2R)-(+)-Norephedrine → Combretastatin A4

Participants

Reaction Steps

Commercially available reagents and solvents were obtained as follows: HPLC-grade solvents, Fisher; anhydrous solvents, Aldrich; diisopropyl azodicarboxylate (DIAD, 95%), Lancaster; 4-aminobenzyl alcohol, Alfa Aesar; Z-val-OSu, Advanced ChemTech; L-citrulline, Novabiochem; (1S, 2R)-(+)-norephedrine and other commercially available reagents, Aldrich. Cbz-val-cit-PAB-OH (1) (Dubowchik, G. M.; Firestone, R. A. Cathepsin B-Sensitive Dipeptide Prodrugs. 1. A Model Study of Structural Requirements for Efficient Release of Doxorubicin. Bioorg. Med. Chem. Letts. 1998, 8, 3341–3346; Dubowchik, G. M.; Mosure, K.; Knipe, J. O.; Firestone, R. A. Cathepsin B-Sensitive Dipeptide Prodrugs. 2. Models of Anticancer Drugs Paclitaxel (Taxol), Mitomycin C and Doxorubicin. Bioorg. Med. Chem. Letts. 1998, 8, 3347–3352) and combretastatin A-4 (VIIIb) (Pettit, G. R.; Singh, S. B.; Boyd, M. R.; Hamel, E.; Pettit, R. K.; Schmidt, J. M.; Hogan, F. Antineoplastic Agents. 291. Isolation and Synthesis of Combretastatin A-4, A-5, and A-6. J Med. Chem. 1995, 38, 1666–1672) were synthesized as previously described. 1H NMR spectra were recorded on a Varian Gemini 300 MHz spectrophotometer. Flash column chromatography was performed using 230–400 mesh ASTM silica gel from EM Science. Analtech silica gel GHLF plates were used for thin-layer chromatography. HPLC was performed using a Waters Alliance system with a photodiode array detector. Combustion analyses were determined by Quantitative Technologies, Inc., Whitehouse, N.J.

Provenance & Evidence