Molecular Simplification in Bioactive Molecules: Formal Synthesis of (+)-Muconin
摘要:
[GRAPHICS]The concept of molecular simplification as a drug design strategy to shorten synthetic routes, while keeping or enhancing the biological activity of the lead drug, has been applied to (+)-muconin, an acetogenin with remarkable cytotoxicity. A novel approach that enables the stereoselective synthesis of such a natural compound or its enantiomer from a common precursor is described. An additional advantage of the method is complete stereochemical control and the decrease in the number of chemical steps required, thus providing an enhancement of the overall yield. Antiproliferative studies against the human solid tumor cell lines showed that the aliphatic chain-THF/THP fragment of (+)-muconin has modest cytotoxic activity. The strategy opens the way to preparing novel bioactive acetogenin analogues by shorter synthetic routes.
Stereoselective Intramolecular Nicholas Reaction Using Epoxides as Nucleophiles
作者:Fernando R. P. Crisóstomo、Tomás Martín、Víctor S. Martín
DOI:10.1021/ol0363570
日期:2004.2.1
[reaction: see text] The intramolecular nucleophilic attack of the epoxides on the exo-Co(2)(CO)(6)-propargylic cations provided cyclic ethers in good yields. The use of substrates with stereochemically defined oxiranes provided polysubstituted tetrahydropyrans and oxepanes with a high degree of stereocontrol. The cyclization is sensitive to the nature of the protecting group used at the primary alcohol