Our objectives were to identify and field test the sex pheromone of female Douglas-fir cone gall midge, Contarinia oregonensis (Diptera: Cecidomyiidae). Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone extract revealed a single compound (A) that elicited responses from male antennae. Hydrogenation of pheromone extract, followed by renewed GC-EAD analysis, revealed a new EAD-active compound with chromatographic characteristics identical to those of tridecan-2-yl acetate on five fused silica columns (DB-5, DB-210, DB-23, SP-1000, and Cyclodex-B). Syntheses, chromatography, and retention index calculations of all possible tridecen-2-yl acetates suggested that the candidate pheromone A was a tridecadien-2-yl acetate with nonconjugated double bonds. Synthetic candidate pheromone component (Z,Z)-4,7-tridecadien-2-yl acetate (Z4Z7) cochromatographed with A on all analytical columns and elicited comparable antennal activity. In GC-EAD analyses that separated the enantiomers (Z,Z)4,7-tridecadien-(S)-2-yl acetate (2S-Z4Z7) and (Z,Z)-4,7-tridecadien-(R)-2-yl acetate (2R-Z4Z7) with baseline resolution, only 2S-Z4Z7 as a component in a racemic standard or in pheromone extract elicited antennal responses. In Douglas-fir seed orchards, sticky traps baited with 2S-Z4Z7 captured male C. oregonensis, whereas 2R-Z4Z7 was behaviorally benign. Comparable catches of males in traps baited with racemic Z4Z7 (50 mug) or virgin female C. oregonensis suggested that synthetic pheromone baits could be developed for monitoring C. oregonensis populations in commercial Douglas-fir seed orchards.
Chiral Surfactant-Type Catalyst for Asymmetric Reduction of Aliphatic Ketones in Water
作者:Jiahong Li、Yuanfu Tang、Qiwei Wang、Xuefeng Li、Linfeng Cun、Xiaomei Zhang、Jin Zhu、Liangchun Li、Jingen Deng
DOI:10.1021/ja308357y
日期:2012.11.14
A novel chiral surfactant-type catalyst is developed. Micelles formed in water by association of the catalysts themselves, and this was confirmed by TEM analyses. Asymmetric transfer hydrogenation of aliphaticketones catalyzed by the chiral metallomicellar catalyst gave good to excellent conversions and remarkable stereoselectivities (up to 95% ee). Synergistic effects between the metal-catalyzed
开发了一种新型手性表面活性剂型催化剂。通过催化剂本身的结合在水中形成胶束,这通过 TEM 分析得到证实。由手性金属胶束催化剂催化的脂肪族酮的不对称转移氢化具有良好到优异的转化率和显着的立体选择性(高达 95% ee)。金属催化中心与金属胶束中核心的疏水微环境之间的协同作用导致高对映选择性。
Cobalt-catalyzed asymmetric hydroboration of aryl ketones with pinacolborane
作者:Jun Guo、Jianhui Chen、Zhan Lu
DOI:10.1039/c5cc01084e
日期:——
The highly enantioselective cobalt-catalyzedhydroboration reaction of aryl ketones with HBpin was developed using iminopyridine oxazoline ligands. Halides, amines, ethers, sulfides, esters and amides are well tolerated under the mild reaction conditions, demonstrating its synthetic advantage. Substituted diaryl ketones could also be hydroborated with high enantioselectivity.
ENANTIOFACE-DIFFERENTIATING HYDROGENATION OF 2-ALKANONES OVER MODIFIED RANEY NICKEL
作者:Tsutomu Osawa
DOI:10.1246/cl.1985.1609
日期:1985.11.5
2-Octanone was hydrogenated over tartaric acid-NaBr-modified Raneynickel in the presence of pivalic acid at various temperatures. The hydrogenation at 50–60 °C gave the best result with regard to the optical yield. Almost 80% of the optical yields were attained in the hydrogenations of various 2-alkanones.
Enantioselective Synthesis of (<i>S</i>)-1-Methyldodecyl Acetate, a Pheromone of<i>Drosophila mulleri</i>, via (-)-Sparteine-Assisted Deprotonation of 1-Dodecanol
作者:Folker Hintze、Dieter Hoppe
DOI:10.1055/s-1992-26340
日期:——
The title compound was synthesized with 98 % ee by enantioselective lithiation and methylation of 1-dodecanol, employing a new protection/activation method for primary alcohols, followed by asymmetric deprotonation of the carbamate.
The present invention provides compounds having the general structure A, or a pharmaceutically acceptable derivatives thereof:
wherein R is an alkyl group, and R
1
comprises at least one moiety selected from a group consisting of an alkyl, an alkenyl, an aryl, a heterocycle, hydroxyl, ester, amido, aldehyde, and a halogen.