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Showing papers by "Chizuko Kabuto published in 1992"



Journal ArticleDOI
TL;DR: In this paper, the intermolecular contacts between chalcogen atoms and cyano lone pairs were found to stabilize the crystalline state by electrostatic interaction, which is one of the sources of the directionality in crystal paccking of organic molecules and causes the formation of various types of inclusion lattices in the charge transfer (CT) crystals of I-3.
Abstract: The intermolecular contacts between chalcogen atoms and cyano lone pairs were found to stabilize the crystalline state by electrostatic interaction. This interaction is one of the sources of the directionality in crystal paccking of organic molecules and causes the formation of various types of inclusion lattices in the charge-transfer (CT) crystals of I-3. By using highly selective formation of CT crystals with substituted aromatic hydrocarbons, particular isomers such as p-xylene or 2,6-dimethylnaphthalene (2,6-DMN) could be separated from the corresponding isomer mixtures

104 citations


Journal ArticleDOI
TL;DR: In this article, the configurational behavior of cyclotetragermanes is described and the crystal structure of [t-Bu(Cl)Ge]4 was established by X-ray diffraction.
Abstract: Condensations of R(Ph)GeCl2 (R = t-Bu and R = CEt2Me) with Mg/MgBr2 in THF produced cyclotetragermanes [R(Ph)Ge]4, which were converted to [R(Cl)Ge]4 by treatment with HCl/AlCl3 or with CF3SO3H followed by CH3COCl. The crystal structure of [t-Bu(Cl)Ge]4 was established by X-ray diffraction. Unusual configurational behavior of cyclotetragermanes is also described.

13 citations


Journal ArticleDOI
TL;DR: In this article, a double Michael-type reaction was developed to synthesize trans-hydroindane from Iµ-Caprolactone, which was transformed into four isomers of methyl 7-methyl-8-oxo-10-(phenylthio)deca-2,9-dienoate.
Abstract: A sulfur-mediated intramolecular double Michael-type reaction stereoselectively producing trans-hydroindanes was developed. Iµ-Caprolactone 3 was transformed into four [(E,E), (E,Z), (Z,E) and (Z,Z)] isomers of methyl 7-methyl-8-oxo-10-(phenylthio)deca-2,9-dienoate (14, 16, 18 and 19). Treatment of these four isomers, 14, 16, 18 and 19, respectively, with tert-butyldimethylsilyl trifluoromethanesulfonate in the presence of triethylamine gave the trans-hydroindane 20 as the main product together, with a small amount of the cis-isomer 22. The annulation was accelerated by the presence of an electron-donating group on the phenylthio group. Substrates 8, 34, 36 and 37, having hydrogen, isopropyl, trimethylsilyl and phenylsulfinyl instead of the sulfenyl group at the 10-position, provided no cyclised product under the same reaction conditions.

7 citations


Journal ArticleDOI
TL;DR: In this paper, the synthesis of the A,B,C and D ring part 17 of diterpene stemodin from 1,4-cyclohexanedione monoethylene ketal 8 by use of the successive intramolecular Diels-Alder reactions is described.

5 citations


Journal ArticleDOI
TL;DR: Phenyl[tris(trimethylsilyl)]ethylene bis(lithium dimethoxyethane) was prepared as black crystals and the molecular structure determined by the X-ray diffraction method showed several interesting features as mentioned in this paper.
Abstract: Phenyl[tris(trimethylsilyl)]ethylene bis(lithium dimethoxyethane) was prepared as black crystals. The molecular structure determined by the X-ray diffraction method shows several interesting features. One of the lithium atoms is located near the central two carbon atoms, while the other is above the benzene ring and the central C–C bond is twisted by 92°.

4 citations


Journal ArticleDOI
TL;DR: In this article, the intermolecular contacts between chalcogen atoms and cyano lone pairs were found to stabilize the crystalline state by electrostatic interaction, which is one of the sources of the directionality in crystal paccking of organic molecules and causes the formation of various types of inclusion lattices in the charge transfer (CT) crystals of I-3.
Abstract: The intermolecular contacts between chalcogen atoms and cyano lone pairs were found to stabilize the crystalline state by electrostatic interaction. This interaction is one of the sources of the directionality in crystal paccking of organic molecules and causes the formation of various types of inclusion lattices in the charge-transfer (CT) crystals of I-3. By using highly selective formation of CT crystals with substituted aromatic hydrocarbons, particular isomers such as p-xylene or 2,6-dimethylnaphthalene (2,6-DMN) could be separated from the corresponding isomer mixtures

3 citations