γ-Lactone Formation in the Addition of Benzenesulfonyl Bromide to Diene and Enyne Esters
摘要:
The gem-dialkyl effect has been used to promote the formation of functionalized gamma-lactones in the addition of benzenesulfonyl bromide to diene and enyne esters. Introduction of 3 mol % of pyridine into the reactions increases the yields of lactones produced from tertiary esters. Formation of the C-alpha-C-beta bond of gamma-lactones has been achieved in both C-alpha-->C beta and C-beta-->C-alpha radical cyclization directions.
[EN] ISOXAZOLOPYRIDINE DERIVATIVES FOR USE IN THE TREATMENT OF HIF-MEDIATED CONDITIONS<br/>[FR] DÉRIVÉS D'ISOXAZOLOPYRIDINE DESTINÉS À ÊTRE UTILISÉS DANS LE TRAITEMENT D'ÉTATS À MÉDIATION PAR HIF
申请人:FIBROGEN INC
公开号:WO2009073669A1
公开(公告)日:2009-06-11
The present invention relates to novel compounds of formula (I) capable of modulating the stability and/or activity of hypoxia inducible factor (HIF) by inhibiting the activity of at least one HIF hydroxylase enzyme.
Selective ene-yne coupling-functionalization: A new strategy in constructing heterocycles
作者:Zhong Wang、Xiyan Lu
DOI:10.1016/0040-4020(95)00035-7
日期:1995.2
Fluorinated derivatives of 3-alkylidene-2(3H)-dihydrofuranone have been synthesized by sodium dithionite initiated tandem perfluoroalkylation-cyclization of allylic 2-alkynoates in fair to good yield and high stereoselectivity. Fluorinated 3-alkylidene-2(3H)-pyrrolidone derivatives were prepared similarly. A mechanistic rationale concerning the different radical steps and the differences between esters
Total Synthesis of (+)-Amphidinolide A. Assembly of the Fragments
作者:Barry M. Trost、Stephen T. Wrobleski、John D. Chisholm、Paul E. Harrington、Michael Jung
DOI:10.1021/ja0533646
日期:2005.10.1
The structure elucidation of (+)-amphidinolide A, a cytotoxic macrolide, has been accomplished by employing a combination of totalsynthesis and NMR spectroscopic analysis. Amphidinolide A possesses two skipped 1,4-diene subunits which are accessible by ruthenium-catalyzed alkene-alkyne couplings. Previous total syntheses had revealed that the reported structure was incorrect; therefore, to incorporate
Palladium (II/IV) catalyzed cyclopropanation reactions: scope and mechanism
作者:Thomas W. Lyons、Melanie S. Sanford
DOI:10.1016/j.tet.2008.10.107
日期:2009.4
This report describes detailed studies of the scope and mechanism of a new Pd-catalyzed oxidation reaction for the stereospecific conversion of enynes into cyclopropyl ketones. Unlike related PdII/0, Au, and Pt-catalyzed cyclopropane-forming reactions, these transformations proceed with net inversion of geometry with respect to the starting alkene. This result, along with other mechanistic data, is
Tetramethyl Thiourea/Co<sub>2</sub>(CO)<sub>8</sub>-Catalyzed Pauson−Khand Reaction under Balloon Pressure of CO
作者:Yefeng Tang、Lujiang Deng、Yandong Zhang、Guangbin Dong、Jiahua Chen、Zhen Yang
DOI:10.1021/ol047651a
日期:2005.2.1
A Pauson-Khandtype of conversion of enynes to bicycliccyclopentenones employing the commercially available Co2(CO)8 and tetramethylthiourea (TMTU) as catalysts is described. This method allows a variety of enynes with diverse functional groups to be cyclized into cyclopentenones of interest. [reaction: see text]