34159-52-9Relevant articles and documents
Preparation of Z-α,β-unsaturated diazoketones from aldehydes. Application in the construction of substituted dihydropyridin-3-ones
Rosset, Isac G.,Burtoloso, Antonio C. B.
, p. 9464 - 9470 (2013/10/08)
The stereoselective preparation of α,β-unsaturated diazoketones with Z geometry is described from aldehydes and a new olefination reagent. When prepared from amino aldehydes, these diazoketones could be converted to substituted dihydropyridin-3-ones in just one step, after an intramolecular N-H insertion reaction. The straightforward synthesis of a natural trihydroxylated piperidine demonstrates the utility of these unsaturated diazoketones for the rapid construction of piperidines.
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.
Synthesis and Properties of Phosphabetaine Structures. I. Reactions of Triphenylphosphine and Triphenyl Phosphite with Unsaturated Carboxylic Acids and Their Derivatives
Galkin,Bakhtiyarova,Polezhaeva,Shaikhutdinov,Klochkov,Cherkasov
, p. 1052 - 1056 (2007/10/03)
Reactions of triphenylphosphine and triphenyl phosphite with unsaturated carboxylic acids and their derivatives yield, depending on the nature of the reactants, phosphobetaine carboxylates, phosphonium salts, functionally substituted phosphonates, and als
