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11.
The title racemate-to-conglomerate transformation which occurs in the solid state on heating or contact with MeOH vapour has been studied by IR and DTA spectral measurements, microscopic observation, and by X-ray structural and X-ray powder diffraction analysis. 相似文献
12.
13.
Some o-xylylene (o-quinodimethane) derivatives were isolated as stable cyrstalline materials. A strong through-bond interaction in tetracyanoethylene addition product of tetraphenylbenzodicyclobutadiene ( is suggested. 相似文献
14.
Akira Okubo Hiroyuki Kawai Toshiro Matsunaga Tatsuji Chuman Sunao Yamazaki Shozo Toda 《Tetrahedron letters》1980,21(42):4095-4096
T1 gives a clue to assign cis- and trans-methyl carbons in 2-methyl-1-propenyl moiety. 相似文献
15.
Fumio Hamada Kyoko Ishikawa Riko Ito Hisanori Shibuya Sanyo Hamai Iwao Suzuki Tetsuo Osa Akihiko Ueno 《Journal of inclusion phenomena and macrocyclic chemistry》1994,20(1):43-51
-Cyclodextrin with two sodium anthranilate moieties (1) has been prepared as a sensor for detecting organic compounds including terpenoids and steroids. Compound1 shows a pure monomer fluorescence whose intensity is increased or decreased upon addition of the guest species examined. In this system, the sodium anthranilate moieties act either as a spacer, which enables the cyclodextrin to form a 1:1 host-guest complex by narrowing the -cyclodextrin cavity, or as a hydrophobic cap.1 recognizes steroids with much higher sensitivity than terpenoids, in which the appended moieties act as a hydrophobic cap for terpenoids and a spacer for steroids, respectively. 相似文献
16.
17.
Mikio Hori Tadashi Kataoka Hiroshi Shimizu Akihiko Tomoto 《Tetrahedron letters》1981,22(37):3629-3632
1-Benzoyl-2-methy1-3,4-dihydro-2-thianaphthalene () underwent novel intermolecular 1,4-rearrangement in refluxing toluene to give an enol ether , while rearrangement of 2-phenyl derivative proceeded intramolecularly in refluxing xylene to afford a 1,4-rearranged enol ether . On the other hand, ylides were refluxed in alcohols to afford some ring-opened products . 相似文献
18.
Hidetake Sakuraba Yoshio Tananaka Fujio Toda 《Journal of inclusion phenomena and macrocyclic chemistry》1991,11(2):195-204
The asymmetric Michael addition of aromatic thiols to 2-cyclohexenone and maleic acid esters has been carried out by utilizing their crystalline cyclodextrin complexes suspended in water. The best chiral induction, 30% enantiomeric excess (ee), was achieved in combinations of 2-cyclohexenone and octyl maleate with the crystalline -cyclodextrin complex of benzenethiol (method A) to afford (S)-3-phenylthiocyclohexanone and (S)-octyl-2-phenylthiosuccinate, respectively, whereas the reaction of benzenethiol with 2-cyclohexenone included in -cyclodextrin (method B) inversely induced the chiral recognition to give the (R)-adduct with 4–9% ee. 相似文献
19.
From a biogenetic point of view, a great variety of related alkaloids isolated from the plant Daphniphyllaceae are related to one another by bond formation or fission. Thus, daphnialcohol acetate (6), a derivative of the degradation products of daphniphylline (1), was subjected to von Braun degradation followed by acid-catalyzed recyclization to give an isomer (8) of daphnialcohol, which has a new type of nitrogen heterocyclic skeleton. Furthermore, daphnilactone-B (3) was converted into a daphniphylline-type compound (19) via a plausible intermediate (21). 相似文献
20.
The retention behavior of lymphocyte subpopulations, B cell, T cell and null cell, derived from rat spleen to polyamine-graft-poly(2-hydroxyethyl methacrylate) copolymer (HA) surface was investigated, focusing on the conformational transition of the polyamine side chain as well as the protonation of amino groups in the polyamine grafts. Furthermore, the availability of HA was discussed as a column adsorbent for separation of lymphocyte subpopulations derived from spleen. The conformational transition of polyamine grafts significantly influenced the mode of retention of lymphocyte subpopulations. When polyamine grafts existed in an aggregated conformation (protonatin degree α < 0.5), the retention of lymphocyte subpopulations was decreased in the order B cell> null cell> T cell. On the other hand, when polyamine existed in an extended conformation into the aqueous interior from the matrix interface (α > 0.5), T cell retention became greater than null cell retention, resulting in a decreased B cell> T cell> null cell order. These results indicate that the differential retention of spleen lymphocyte subpopulations is attributed to their differential responses to the change in matrix interface accompanied by the protonation of amino groups. Furthermore, spleen lymphocytes were compared with lymph node lymphocytes in terms of resolution efficacy by an HA copolymer column. 相似文献