82188-73-6Relevant articles and documents
Total Synthesis of Kadcoccinic Acid A Trimethyl Ester
Gholami, Hadi,Trost, Barry M.,Zell, Daniel,Zhang, Guoting
supporting information, p. 12286 - 12293 (2021/08/20)
The first total synthesis of the trimethyl ester of kadcoccinic acid A is described. The central structural element of our synthesis is a cyclopentenone motif that allows the assembly of the natural product skeleton. A gold(I)-catalyzed cyclization of an enynyl acetate led to efficient construction of the cyclopentenone scaffold. In this step, optimization studies revealed that the stereochemistry of the enynyl acetate dictates regioisomeric cyclopentenone formation. The synthesis further highlights an efficient copper-mediated conjugate addition, merged with a gold(I)-catalyzed Conia-ene reaction to connect the two fragments, thereby forging the D-ring of the natural product. The synthetic strategy reported herein can provide a general platform to access the skeleton of other members of this family of natural products.
Bridgehead Modifications of Englerin A Reduce TRPC4 Activity and Intravenous Toxicity but not Cell Growth Inhibition
Wu, Zhenhua,Suppo, Jean-Simon,Tumova, Sarka,Strope, Jonathan,Bravo, Fernando,Moy, Melody,Weinstein, Ethan S.,Peer, Cody J.,Figg, William D.,Chain, William J.,Echavarren, Antonio M.,Beech, David J.,Beutler, John A.
supporting information, p. 1711 - 1716 (2020/10/19)
Modifications at the bridgehead position of englerin A were made to explore the effects of variation at this site on the molecule for biological activity, as judged by the NCI 60 screen, in which englerin A is highly potent and selective for renal cancer cells. Replacement of the isopropyl group by other, larger substituents yielded compounds which displayed excellent selectivity and potency comparable to the natural product. Selected compounds were also evaluated for their effect on the ion channel TRPC4 as well as for intravenous toxicity in mice, and these had lower potency in both assays compared to englerin A.
Enantioselective Total Synthesis of Cotylenin A
Nagatani, Kotaro,Nakada, Masahisa,Osada, Ryunosuke,Sugiyama, Ryoji,Uwamori, Masahiro
supporting information, p. 5556 - 5561 (2020/04/10)
A convergent enantioselective total synthesis of cotylenin A is described. The A-ring fragment, prepared via the catalytic asymmetric intramolecular cyclopropanation developed in our laboratory, and the C-ring fragment, prepared from a known chiral compound via a modified acyl radical cyclization, were successfully assembled by the Utimoto coupling reaction. The formidable carbocyclic eight-membered ring of cotylenin A was efficiently constructed by a palladium-mediated cyclization. All the hydroxy groups in the scaffold were stereoselectively introduced, and a modified reducing reagent, Me4NBH(O2CiPr)3, has been developed. The sugar moiety fragment was prepared via three consecutive carbon-oxygen bond-forming reactions, and the glycosylation was accomplished using Wan's protocol.
