To discover new phenanthroindolizidine and phenanthroquinolizidine alkaloids as potential anticancer drugcandidates, non-natural 6-O-desmethylcryptopleurine (2) and its derivatives were prepared. Most of the new compounds exhibited potent antiproliferative activity against A549 and BEL-7402 cells, with the lowest IC50 being 3 nM. Optically pure 2-R was further evaluated against a panel of 30 cancer