34159-52-9Relevant academic research and scientific papers
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.
Z-selective intramolecular horner-wadsworthemmons reaction for the synthesis of macrocyclic lactones
Ando, Kaori,Narumiya, Kenji,Takada, Hirokazu,Teruya, Taiji
scheme or table, p. 1460 - 1463 (2010/06/15)
(Figure Presented) When the substrates (ArO)2P(O)CH 2CO2...CHO (Ar = Ph, o-tBuPh) were added to a THF solution containing 3 equiv of NaH at 0 °C or Nal DBU at rt over 1-10 h, the intramolecular Horner-Wadsworth-Emmons reaction proceeded efficiently to give the 12-18-membered-ring lactones in 69-93% yields with 89-100% Z selectivity. On the other hand, (EtO)2P(O)CH2CO2-GHO gave the 13-18-membered-ring lactones in 52-82% yields with 89-99% E selectivity using LiCI-DBU in MeCN or THF.
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.
A macrolactonization-based strategy to obtain microtuble-stabilizing agent (-)-laulimalide
Ghosh, Arun K,Wang, Yong
, p. 3399 - 3401 (2007/10/03)
An alternative synthesis of anti-tumor macrolide (-)-laulimalide is described. The synthesis was achieved utilizing Yamaguchi macrolactonization as the key step. The sensitive C2-C3 cis-olefin functionality has been installed by a ma
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
