Camptothecin derivatives and improved synthetic methods
申请人:Shull Keith Brian
公开号:US20070099948A1
公开(公告)日:2007-05-03
The present invention relates to compositions and methods for preparing pharmaceutical compositions. In some embodiments, the invention includes compounds and methods of resolving chiral compounds. In some embodiments, the invention includes chiral and crystalline compositions and hydrates. In some embodiments, the invention contemplates compositions comprising camptothecin derivatives and synthetic intermediates thereof. In some embodiments, the invention includes methods of protecting, inserting, modifying, separating isomers, and removing chemical groups.
A stereoselectivesynthesis of the LM-ring fragment has been achieved starting from a sugar derivative. A stereoselectivesynthesis of the JKLM-ring fragment has been achieved through a coupling between two segments via heteroconjugate addition, seven-membered ether ring formation mediated by an acetylene cobalt complex, and spiroketalization reaction.
High selectivity in heteroconjugate addition for C—C bond formation with complete syndiastereoselection has been attributed to the chelation effect between the α-oxygen atom of the substrate and the nucleophile anions through metal cations. Herein is described a new method exhibiting antidiastereoselection based on a different chelation effect caused by the ligands on the β-carbon atom to the heteroolefin
[EN] TRANSACETALISATION PROCESS<br/>[FR] METHODE DE TRANSACETALISATION
申请人:UNIV MONASH
公开号:WO2005070911A1
公开(公告)日:2005-08-04
The invention relates to the resolution of racemic mixtures, and in particular to the separation of enantiomers of chiral alcohols utilising recyclable chiral auxiliaries. The present invention also relates to a process for preparing these recyclable chiral auxiliaries using an enantiomerically pure alcohol.
Mirror Image Synthesis of Left Ends of Ciguatoxin and Gambiertoxin 4b
作者:Seijiro Hosokawa、Minoru Isobe
DOI:10.1021/jo980088n
日期:1999.1.1
Three compoundsrelated to the AB fragments of ciguatoxin and gambiertoxin 4b and two diastereomers (at the C-2 position) of the ABC fragment of ciguatoxin have been synthesized in enantiomeric form. The stereochemistry of the C-2 position was introduced selectively from the corresponding pentose derivative. Construction of the A ring with its side chain was completed by Nicholas type cyclization of