Studies on pyrazines. Part 32. Synthesis of trisubstituted and tetrasubstituted pyrazines as ant pheromones
作者:Nobuhiro Sato、Tomoyuki Matsuura
DOI:10.1039/p19960002345
日期:——
The synthesis of trialkylpyrazines having methyl groups on C-2 and C-5 is described, which is completed by the cross-coupling reaction of 2-chloro-3,6-dimethylpyrazine with dialkylzinc in the presence of [1,3-bis(diphenylphosphino)propane] nickel(II) chloride. Similarly, 2,5-diisobutyl-, -diisopropyl- and -di-sec-butyl-3-methylpyrazines are prepared from the corresponding dialkyl chloropyrazines. The dimethyl products are acylated with an α-keto acid under the Minisci radical conditions providing 2-acyl-5-alkyl-3,6-dimethylpyrazines. Several compounds obtained in this study prove to be active as components of pheromones in ants.
quantitative yield, along with their solid state self-assembling properties. This process is extremely simple and highly efficient with little or no traditional synthetic skills and without any chromatographic purification. Synthesis of structurally diverse DKPs has been achieved with a dramatic decrease in the reaction time, the amount/number of solvents used, a significant increase in the yield and nearly complete
Untersuchungen über stereoisomere Salze des Leucin-methylesters
作者:K. Weil、Werner Kuhn
DOI:10.1002/hlca.19460290404
日期:——
Löslichkeiten diastereomerer Salze von d(−)- und von l(+)-Leucin-methylester mit optischaktiven Säuren untersucht. Aus solchen Löslichkeitsbestimmungen lassen sich Schlüsse ziehen auf die Verwendbarkeit der einzelnen Säuren für die Eliminierung des im natürlichen Leucin in grosser Menge vorhandenen häufigen und damit für eine Anreicherung des seltenen Antipoden.
The reaction of amino acids and phosphorustrichloride in THF was studied by 31P NMR tracing and ESI‐MS/MS. A series of hydridophoranes and cyclic dipeptides were obtained. The reaction presented interesting diversity and the reaction mechanism was proposed. The mechanism suggests that phosphorus plays an important role in the synthesis of amino acid hydridophorane and cyclic dipeptides. The results
通过31 P NMR示踪和ESI-MS / MS研究了氨基酸与三氯化磷在THF中的反应。获得了一系列的氢杂环丙烷和环状二肽。反应呈现出有趣的多样性,并提出了反应机理。该机理表明磷在氨基酸氢庚烷和环状二肽的合成中起着重要作用。结果还表明,31 P NMR和ESI-MS / MS是研究反应机理的有用工具。
Multi-valent guanidinium compounds for enhancing molecular translocation across cellular membranes and epithelial tissues
申请人:Hou Zheng
公开号:US20070078078A1
公开(公告)日:2007-04-05
Disclosed herein are guanidinium containing compounds consisting of a core moiety with a plurality of side chains containing guanidinium groups. Such compounds have enhanced translocation across cellular membranes and epithelial tissues. The compounds may also have a therapeutic or other biologically active moiety attached so that these moieties may be effectively transported into a cell by the guanidinium containing compound.