A general stereoselective method for the synthesis of cyclopropanecarboxylates. A new version of the homologous Horner–Wadsworth–Emmons reaction
作者:Henryk Krawczyk、Katarzyna Wąsek、Jacek Kędzia、Jakub Wojciechowski、Wojciech M. Wolf
DOI:10.1039/b712145h
日期:——
The synthesis of α-, β- and γ-substituted α-phosphono-γ-lactones was accomplished using different ring closure and ring homologation strategies. It was found that the lactones could be selectively transformed into the corresponding ethyl cyclopropanecarboxylates by treatment with sodium ethoxide in boiling THF. The reported reaction provides an attractive alternative to the classical homologous HornerâWadsworthâEmmons approach to the construction of cyclopropanes with electron-withdrawing functionalities.
Elimination and addition reactions. Part 30. Leaving group abilities in alkene-forming eliminations activated by sulphonyl groups
作者:Donald R. Marshall、Patsy J. Thomas、Charles J. M. Stirling
DOI:10.1039/p29770001898
日期:——
Rates of elimination of the group Z from a series of β-substituted sulphones, PhSO2·CH2·CH2Z, in ethanolic sodium ethoxide at 25 °C have been measured. For each substrate, the mechanism of the reaction has been shown to be the reversible carbanion mechanism [(E1cB)R] by determination of the primary kinetic deuterium isotope effect or by demonstration that deuterium-hydrogen exchange at Cβ is very much
SURFACE-MEDIATED SOLID PHASE REACTIONS: MICROWAVE ASSISTED ARBUZOV REARRANGEMENT ON THE SOLID SURFACE
作者:B. Kaboudin、M. S. Balakrishna
DOI:10.1081/scc-100105324
日期:2001.1
Microwave assisted Arbuzov rearrangement under solvent-free condition was found to be an efficient method for the preparation of dialkyl alkylphosphonates of alkyl halides. This method is an easy, rapid, and high-yielding reaction for the Arbuzov rearrangement.
γ-Substituted Bis(pivaloyloxymethyl)ester Analogues of Fosmidomycin and FR900098
作者:Thomas Kurz、Christoph Behrendt、Miriam Pein、Uwe Kaula、Bärbel Bergmann、Rolf D. Walter
DOI:10.1002/ardp.200700107
日期:2007.12
The synthesis and in‐vitro antimalarial activity of γ‐substituted bis(pivaloyloxymethyl)esteranalogues of the drug candidate fosmidomycin have been investigated. In contrast to the high antimalarial activity of α‐aryl substituted fosmidomycinanalogues like α‐phenylfosmidomycin, γ‐substituted derivatives display only weak to moderate activity against the chloroquine‐sensitive strain 3D7 of Plasmodium