Dihydrocolchicine 8,12-Endoperoxide: A Novel Starting Material for Convenient Syntheses of the AllocolchicinoidsN-AcetylcolchinolO-Methyl Ether and Androbiphenyline
作者:René Brecht、Frank Haenel、Gunther Seitz
DOI:10.1002/jlac.199719971115
日期:1997.11
dihydrocolchicine-8,12-endoperoxide 2 is used as the startingmaterial for the synthesis of some bioactive allocolchicinoids. Depending on the reaction conditions and reagents employed, different modifications of the C ring of colchicine (1) are achieved. Triphenylphosphane deoxygenation of 2 leads to the well known N-acetylcolchinol O-methyl ether (NCME, 6, 40% yield from 1). Treatment of the endoperoxide
Novel B-ring modified allocolchicinoids of the NCME series: design, synthesis, antimicrotubule activity and cytotoxicity
作者:Silke Bergemann、René Brecht、Frank Büttner、Daniel Guénard、Ronald Gust、Gunther Seitz、Milton T. Stubbs、Sylviane Thoret
DOI:10.1016/s0968-0896(02)00639-9
日期:2003.4
In the second series the seven-membered B-ring of NCME (2) was modified by annulation with a heterocyclic ring system. The racemic ketone 7a serving as key precursor involved in the syntheses of all the target NCME variants 9-13 and 15, 16 was easily transformed into the eight-membered B-ring lactams 9 and 10 via a Beckmann rearrangement of the corresponding E-oxime 8. The tetrazole annulated congener