D-ring substituted rhazinilam analogues: Semisynthesis and evaluation of antitubulin activity

Novel (-)- and (+)-rhazinilam derivatives substituted on the D-ring (compou nds 3, 4, 5 and 6) have been prepared from (+)-vincadifformine 7 and (-)-ta bersonine and evaluated against the disassembly of microtubules into tubuli n. Along with this study, a reproducible 'one pot' semisynthesis of (-)-rha zinilam 1 from (+)-1,2-didehydroaspidospermidine 2 was performed allowing t he easy preparation of these new compounds. (C) 1999 Elsevier Science Ltd. All rights reserved.