110786-78-2Relevant articles and documents
Amphidinolide B: Total synthesis, structural investigation, and biological evaluation
Lu, Liang,Zhang, Wei,Nam, Sangkil,Horne, David A.,Jove, Richard,Carter, Rich G.
, p. 2213 - 2247 (2013/05/09)
The total syntheses of amphidinolide B1 and the proposed structure of amphidinolide B2 have been accomplished. Key aspects of this work include the development of a practical, non-transition-metal-mediated method for the construction of the C13-C15 diene, the identification of α-chelation and dipole minimization models for diastereoselective methyl ketone aldol reactions, the discovery of a spontaneous Horner-Wadsworth-Emmons macrocyclization strategy, and the development of a novel late stage method for construction of an allylic epoxide moiety. The originally proposed structure for amphidinolide B2 and diastereomers thereof display potent antitumor activities with IC50 values ranging from 3.3 to 94.5 nM against human solid and blood tumor cells. Of the different stereoisomers, the proposed structure of amphidinolide B2 is over 12-fold more potent than the C8,9-epimer and C18-epimer in human DU145 prostate cancer cells. These data suggest that the epoxide stereochemistry is a significant factor for anticancer activity.
Total syntheses of amphidinolides B1, B4, G1, H1 and structure revision of amphidinolide H2
Fuerstner, Alois,Bouchez, Laure C.,Morency, Louis,Funel, Jaques-Alexis,Liepins, Vilnis,Poree, Francois-Hugues,Gilmour, Ryan,Laurich, Daniel,Beaufils, Florent,Tamiya, Minoru
experimental part, p. 3983 - 4010 (2009/12/22)
Dinoflagellates of the genus Amphidinium produce a "library" of closely related secondary metabolites of mixed polyketide origin, which are extremely scarce but highly promising owing to the exceptional cytotoxicity against various cancer cell lines. Because of the dense array of sensitive functionalities on their largely conserved macrocyclic frame, however, these amphidinolides of the B, D, G and H types elapsed many previous attempts at their synthesis. Described herein is a robust, convergent and hence general blueprint which allowed not only to conquest five prototype members of these series, but also holds the promise of making "non-natural" analogues available by diverted total synthesis. This notion transpires for a synthesis-driven structure revision of amphidinolide H2. The successful route hinges upon a highly productive Stille-Migita cross-coupling reaction at the congested and chemically labile 1,3-diene site present in all such targets, which required the development of a modified chloride- and fluoride-free protocol. The macrocyclic ring could be formed with high efficiency and selectivity by ring-closing metathesis (RCM) engaging a vinyl epoxide unit as one of the reaction partners. Because of the sensitivity of the targets to oxidizing and reducing conditions as well as to pH changes, the proper adjustment of the protecting group pattern for the peripheral -OH functions also constitutes a critical aspect, which has to converge to silyl groups only once the diene is in place. Tris(dime-thylamino)sulfomum difluorotrimethyl-silicate (TASF) turned out to be a sufficiently mild fluoride source to allow for the final deprotection without damaging the precious macrolides.
