(<i>S</i>)-2-Pentyl (<i>R</i>)-3-Hydroxyhexanoate, a Banana Volatile and Its Olfactory Recognition by the Common Fruit Fly, <i>Drosophila melanogaster</i>
The volatile organic compounds emitted from ripening bananas that elicit an antennal response from the common fruit fly, Drosophila melanogaster, were analyzed by a combination of gas chromatographic−electroantennographic detection, mass spectrometry, and 1H NMR spectroscopy. These analyses revealed that the headspace of ripening bananas contains a number of EAD-active components including the new
结合了气相色谱-电电图,质谱和1 H NMR光谱分析了成熟香蕉发出的挥发性有机化合物,这些香蕉引起了普通果蝇果蝇的触角反应。这些分析表明,成熟香蕉的顶部空间包含许多EAD活性成分,包括新的酯(S)-2-戊基(R)-3-羟基己酸酯,其结构分配已通过化学合成得到证实。
Mechanistically Guided Design of an Efficient and Enantioselective Aminocatalytic α-Chlorination of Aldehydes
The enantioselective aminocatalytic α-chlorination of aldehydes is a challenging reaction because of its tendency to proceed through neutral intermediates in unselective pathways. Herein we report the rational shift to a highly selective reaction pathway involving charged intermediates using hexafluoroisopropanol as solvent. This change in mechanism has enabled us to match and improve upon the yields
A General Method for the Synthesis of Nonracemic <i>trans</i>-Epoxides: Concise Syntheses of <i>trans</i>-Epoxide-Containing Insect Sex Pheromones
作者:Baldip Kang、Robert Britton
DOI:10.1021/ol702273n
日期:2007.11.1
developed that provides rapid access to alkyl-, alkenyl-, alkynyl-, and phenyl-substituted trans-epoxides from aldehydes. This methodology has also been applied in concise and high-yielding syntheses of both trans-epoxide containing insect sex pheromones.
Enantioselective α-Chlorination of Aldehydes with Recyclable Fluorous (S)-Pyrrolidine-Thiourea Bifunctional Organocatalyst
作者:Chun Cai、Wei Zhang、Liang Wang、Dennis Curran
DOI:10.1055/s-0029-1219198
日期:2010.2
A novel fluorous (S)-pyrrolidine-thiourea bifunctional organocatalyst is prepared. The catalyst shows good activity and enantioselectivity for direct α-chlorination of aldehydes using N-chlorosuccinimide (NCS) as the chlorine source. It can be recovered from the reaction mixture by fluorous solid-phase extraction with excellent purity for direct reuse.
A tandem, proline-catalyzed alpha-chlorination/aldol reaction is described that involves a dynamic kinetic resolution of alpha-chloroaldehyde intermediates. The resulting syn-chlorohydrins are produced with good to excellent diastereoselectivity in high enantiopurity and provide new opportunities for the synthesis of carbohydrates.