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81.
82.
Thermolyses of cage lactones () and their corresponding lactols () cause a formal dyotropic rearrangement. These novel reactions in cage system are discussed. 相似文献
83.
Tsutomu Kumagai Kazuya Murakami Hajime Hotta Toshio Mukai 《Tetrahedron letters》1982,23(45):4705-4708
Upon irradiation, 5-dicyanomethylenebicyclo[2.2.2]octene () gives a highly strained compound, 2,2-dicyanotricyclo[4.2.1.01,3]nonene () in good yield. Of additional interest is the observation that the starting material can be quantitatively regenerated from the photo-product with release of 28.8 kcal/mol. 相似文献
84.
85.
Mukai C Kobayashi M Kubota S Takahashi Y Kitagaki S 《The Journal of organic chemistry》2004,69(6):2128-2136
A new procedure for constructing monocyclic five- and six-membered azacycles by the endo-mode ring-closing reaction of allenylazido derivatives under neutral conditions has been developed. The azabicyclo[m.n.0] compounds were prepared by applying this newly developed procedure. The seven-membered azacycle was prepared when the allene possessing an unsubstituted carboxyl amido functionality was submitted to the basic conditions. In addition, indole and quinoline skeletons were synthesized using this procedure. 相似文献
86.
Mukai R Horino Y Tanaka S Tamaru Y Kimura M 《Journal of the American Chemical Society》2004,126(36):11138-11139
Pd(0).Et3B catalyzes amphiphilic activation of symmetric allylic diol 1 to promote electrophilic allylation at the alpha-position of aldehydes and nucleophilic allylation at the aldehyde CO, furnishing 3-methylenecyclopentalols 2 and thus generation of a zwitterionic trimethylenemethane species from the commercially available diol 1. 相似文献
87.
Spectral hole in the amplified spontaneous emission spectrum of a fiber optical parametric amplifier
The amplified spontaneous emission (ASE) spectrum of a fiber optical parametric amplifier in a gain-saturation condition is studied. We experimentally observed holes around the signal and the idler in the ASE spectrum of a deeply gain-saturated amplifier. This observation is explained by a theoretical model that includes parametric interactions among ASE components and the pump, signal, and idler beams. 相似文献
88.
Yukari Tajika Yumi Yasuoka Hiroyuki Nagahama Toshiyuki Suzuki Yoshimi Homma Tetsuo Ishikawa Shinji Tokonami Takahiro Mukai Miroslaw Janik Atsuyuki Sorimachi Masahiro Hosoda 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(3):1709-1714
Gas-flow ionization chambers for radioisotope (RI) monitoring systems at RI institutes throughout Japan are commonly used to measure RIs which leak from the RI institutes. Before the Japan’s 2011 Tohoku earthquake [11 March 2011, moment magnitude (M w) 9.0], ionization current data measured with a gas-flow ionization chamber at the RI institute of Fukushima Medical University were found to change. The question we must raise is whether the variation ionization current can be considered to the variation of outdoor radon concentration. The conversion factors (from ionization current to radon concentration in air) of the gas-flow ionization chamber can be obtained by measuring four levels of radon concentration (outdoor air, indoor air, high level and radon-free gas) with an AlphaGUARD monitor and the chamber itself. The two gas-flow ionization chambers consist of the air intake and terminal exhaust duct of the RI institute. It was found that the radon concentration in the exhaust air was the same as that in the air intake. This study provided evidence that variations of outdoor radon concentration could be determined using gas-flow ionization chambers for RI monitoring systems. 相似文献
89.
Yasuaki Kawaguchi Shigeo Yasuda Akira Kaneko Yuki Oura Chisato Mukai 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(29):7738-7742
The efficient RhI‐catalyzed cycloisomerization of benzylallene‐alkynes produced the tricyclo[9.4.0.03,8]pentadecapentaene skeleton through a C H bond activation in good yields. A plausible reaction mechanism proceeds via oxidative addition of the acetylenic C H bond to RhI, an ene‐type cyclization to the vinylidenecarbene–RhI intermediate, and an electrophilic aromatic substitution with the vinylidenecarbene species. It was proposed based on deuteration and competition experiments. 相似文献
90.
[reaction: see text] The Stille coupling of N-acyl-2-iodoanilines with the 1-(tributylstannyl)-1-substituted allenes affected the successive one-step formation of the 2-methyl-3-substituted indoles. Alternatively, the other type of 2-alkyl-3-substituted indoles could be synthesized in a one-pot operation, which consists of the Stille coupling reaction with the 1-(tributylstannyl)-1,3-disubstituted allenes, followed by TBAF treatment. This procedure could be applied to the synthesis of indomethacin. 相似文献