The synthesis of tamandarin B is described. Key steps in the synthesis of the macrocycle component include a diastereoselective ketone reduction, linear precursor formation via an activated pentafluorophenyl ester, and HATU-promoted cyclization. Side-chain coupling was achieved in excellent yield with the newly developed coupling reagent DEPBT. (C) 2000 Published by Elsevier Science Ltd.
Total Syntheses and Biological Investigations of Tamandarins A and B and Tamandarin A Analogs
摘要:
Tamandarins A (1) and B (2), two natural products similar in structure to didemnin B (3), were recently isolated from a Brazilian marine ascidian of the family Didemnidae. The cytotoxicity of 1 was reported to be somewhat more potent in vitro than that of 3 against various human cancer cell lines. The present account describes the first total syntheses of 1 and 2, and the syntheses of tamandarin A side chain analogues. The cytotoxicity data for these compounds show that the side chain modifications exhibit a parallel effect for both didemnins and tamandarins. This observation supports tamandarins' role as didemnins' mimic.
Enantiomerically pure pyrrolidine-2,4-diones (tetramic acids) which can be diastereoselectively hydrogenated to syn-statines (4-amino-3-hydroxy-6-methylheptanoic acids) have been prepared by catalytic hydrogenation of 4-(benzyloxycarbonylamino)-3-oxocarboxylic acid esters.
Tamandarin analogs and fragments thereof and methods of making and using
申请人:Joullie M. Madeleine
公开号:US20070149446A1
公开(公告)日:2007-06-28
The present invention is directed to a compound of Formula I wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, W, X, Y, and Z are defined herein. The compounds of the present invention are useful as anticancer agents. Specifically, the compounds are useful for treating or preventing cancer and tumor growth. The present invention is also directed to compositions comprising a compound according to the above formula. The present invention is also directed to methods of using a compound according to the above formula.