273733-91-8Relevant academic research and scientific papers
Synthesis of Linear (Z)-α,β-Unsaturated Esters by Catalytic Cross-Metathesis. The Influence of Acetonitrile
Yu, Elsie C.,Johnson, Brett M.,Townsend, Erik M.,Schrock, Richard R.,Hoveyda, Amir H.
, p. 13210 - 13214 (2016)
Kinetically controlled catalytic cross-metathesis reactions that generate (Z)-α,β-unsaturated esters selectively are disclosed. A key finding is that the presence of acetonitrile obviates the need for using excess amounts of a more valuable terminal alken
Total synthesis of microtubule-stabilizing agent (-)-laulimalide
Ghosh,Wang,Kim
, p. 8973 - 8982 (2007/10/03)
An enantioselective first total synthesis of laulimalide (1) is described. Laulimalide, a remarkably potent antitumor macrolide, has been isolated from the Indonesian sponge Hyattella sp. and the Okinawan sponge Fasciospongia rimosa. Laulimalide represents a new class of antitumor agents with significant clinical potential. The synthesis is convergent and involved the assembly of C3-C16 segment 4 and C17-C28 segment 5 by Julia olefination. The sensitive C2-C3 cis-olefin functionality was installed by Yamaguchi macrolactonization of a hydroxy alkynic acid followed by hydrogenation of the resulting alkynoic lactone over Lindlar's catalyst. Initial attempts of intramolecular Still's variant of Horner - Emmons olefination between the C19-phosphonocetate and C3-aldehyde provided a 1:2 mixture of cis- and trans-macrolactones. The trans-isomer was photo-isomerized to a mixture of cis- and trans-isomers. The other key steps involved ring-closing olefin metathesis to construct both dihydropyran units, stereoselective anomeric alkylation to functionalize the dihydropyran ring, stereoselective reduction of the resulting alkynyl ketone to set the C20-hydroxyl stereochemistry, and a novel Julia olefination protocol for the installation of the C13-exomethylene unit. The sensitive epoxide at C16-C17 was introduced in a highly stereoselective manner by Sharpless epoxidation at the final stage of the synthesis.
An enantioselective synthesis of the C2-C16 segment of antitumor macrolide laulimalide
Ghosh, Arun K.,Wang, Yong
, p. 2319 - 2322 (2007/10/03)
An enantioselective synthesis of the C2-C16 segment of the novel antitumor agent laulimalide is described. The key steps involve a highly diastereoselective allylation, ring-closing olefin metathesis of a homoallylic alcohol derived acrylate ester, a stereoselective anomeric alkylation and an elaboration of an exo-methylene unit by a Julia olefination reaction. (C) 2000 Elsevier Science Ltd.
