Unnatural C-1 homologues of pancratistatin - Synthesis and promising biological activities.

Several C-1 homologues of pancratistatin and 7-deoxypancratistatin were synthesized by a phenanthrene-phenathridone oxidative recyclization strategy. The key steps involved the enzymatic dihydroxylation of bromobenzene, addition of an aryl alane to an epoxyaziridine, an intramolecular aziridine opening on silica gel in solid phase, and the above-mentioned recylization strategy. Experimental and spectral data are reported for all new compounds. All synthesized C-1 homologues of pancratistatin and 7-deoxypancratistatin were evaluated for antiproliferative activity in a panel of human cancer cell lines. As expected, the 7-hydroxy compounds were found to be more potent and the activity of the C-1 benzoxymethyl analogue exceeded that of narciclasine, which was used as a positive control.