Synthesis and antimalarial activity of 6-cycloalkylvinyl substituted 1,2,4-trioxanes
作者:Chandan Singh、Naveen Chandra Srivastav、Sunil K. Puri
DOI:10.1016/j.bmc.2004.08.042
日期:2004.11
6-Cycloalkylvinyl substituted 1,2,4-trioxanes 6-15 have been prepared and tested against multi-drug resistant Plasmodium yoelii in mice. The most active trioxane 11 provides 80% protection to the treated mice. Further derivatization of 11 leads to decrease in antimalarial activity.
Selective isomerization of electron deficient vinylcyclopropanes by thermal action of pentacarbonyl iron
作者:Matthias M. Schulze、Ulrich Gockel
DOI:10.1016/0040-4039(95)02204-x
日期:1996.1
variety of vinylcyclopropanes, bearing an ester group in the β-position, upon expose to pentacarbonyl iron at elevated temperatures is established. Dienic esters with a single configuration of the double bonds are obtained by this route in high yield. Steric and electronic factors, governing the course of the reactions, were investigated using nitrile and alkyl substituted vinylcyclopropanes.
Conformational Dynamics of Tetraisopropylmethane and of Tetracyclopropylmethane<sup>1</sup>
作者:J. Edgar Anderson、Armin de Meijere、Sergei I. Kozhushkov、Lodovico Lunazzi、Andrea Mazzanti
DOI:10.1021/ja017526j
日期:2002.6.1
Tetraisopropylmethane (1) exists in solution as a mixture of two types of conformers (D(2d) and S(4) time-averaged symmetry) in the ratio 93:7 at - 110 degreesC, interconverting with a barrier of 9.7 kcal mol(-1). Molecular mechanics calculations and the multiplicity of NMR signals at low temperature allow the assignment of these conformations. The only conformation populated in tetracyclopropylmethane (2) is the same type as the minor conformation (S(4) time-averaged symmetry) populated in 1. 13 C NMR spectra at about -180 degreesC show that degenerate versions of this conformation interconverting with a barrier of 4.5 kcal mol-1. Molecular mechanics calculations that characterize the six possible conformational types for these molecules, and the most important interconversion pathways, are reported. Calculated and experimental barriers match satisfactorily well.
Tetracyclopropylmethane: A Unique Hydrocarbon with S4 Symmetry
作者:Sergei I. Kozhushkov、Rafael R. Kostikov、Alexander P. Molchanov、Roland Boese、Jordi Benet-Buchholz、Peter R. Schreiner、Christopher Rinderspacher、Ion Ghiviriga、Armin de Meijere