The first totalsynthesis of (−)-merrillianin (1), which is a natural sesquiterpene with a tricyclic structure having a cyclopentane ring and five- and seven-membered lactone parts, is demonstrated. This asymmetric totalsynthesis enabled the absolute stereostructure determination of naturally occurring (−)-1.
Octalactin A, an antitumor agent containing an eight-membered lactone moiety, has been stereoselectively prepared by means of enantioselective aldol reactions of selected silyl enolates with achiral aldehydes, promoted by a chiral Sn(II) complex. The medium-sized lactone part was effectively constructed by way of a new and rapid mixed-anhydride lactonization using 2-methyl-6-nitrobenzoic anhydride
First total synthesis of the E- and Z-isomers of cytospolide-D
作者:Ahmed Kamal、Moku Balakrishna、Papagari Venkat Reddy、Abdul Rahim
DOI:10.1016/j.tetasy.2013.12.004
日期:2014.1
A simple, convergent, and efficient approach for the totalsynthesis of the bioactive E- and Z-isomers of cytospolide-D is described. The key features of the synthetic strategy include stereoselective methylation, regioselective epoxide opening, olefincross-metathesis, and a Yamaguchi protocol reaction for the formation of the E-olefinic geometry of the 10 membered ring; Steglich esterification and