Showing papers by "Chizuko Kabuto published in 1990"
TL;DR: The bridged, pentacyclic intermediate 2 for atisine was synthesized in a naturally occurring enantiomeric form from dimethyl cyclohexanone-2,6-dicarboxylate (6) as mentioned in this paper.
Abstract: The bridged, pentacyclic intermediate 2 for atisine (1) was synthesized in a naturally occurring enantiomeric form from dimethyl cyclohexanone-2,6-dicarboxylate (6). The synthesis is composed of the following key steps: (1) formation of the azabicyclo [3.3.1] nonane by a double Mannich reaction, (2) enantioselective conversion by a lipase-catalyzed acylation, (3) stereoselective hydroboration in the presence of BF 3 .Et 2 O, and (4) construction of the bicyclo [2.2.2] octane ring system by an intramolecular double Michael reaction
75 citations
66 citations
15 citations
TL;DR: The crystal and molecular structure of the title compound has been determined by the use of the X-ray diffraction method as discussed by the authors, and the central metal atom coordinates all four of the nitrogen atoms of N,N′-dimethyl 2,11-diaza[3.3]-pyridinophane and two additional chloride atoms in an approximately octahedral geometry.
Abstract: The crystal and molecular structure of the title compound has been determined by the use of the X-ray diffraction method. The central metal atom coordinates all four of the nitrogen atoms of N,N′-dimethyl 2,11-diaza[3.3](2,6)-pyridinophane and two additional chloride atoms in an approximately octahedral geometry.
11 citations
TL;DR: Tetragerma[2.2]paracyclophane bridged by two GeGe bonds has been prepared by the reductive coupling reaction of 1,4-bis(chlorodimethylgermyl)benzene with sodium as mentioned in this paper.
8 citations
TL;DR: In this article, the tricarbonyliron complexes of the 8.8-Chloro-8-cyano-1,2-homoheptafulvene and its tricarbone-iron complexes have been investigated.
Abstract: 8-Chloro-8-cyano-1,2-homoheptafulvene and its tricarbonyliron complexes have been prepared. Their structures and optical activities were investigated.
4 citations
TL;DR: In this article, the title compound and related poly(disilanyl)ethylenes were prepared by the reaction of 1,2-bis(bromodimethylsilyl)-1,2bis(chlorodimethyllithium)ethylene with trimethyl silylithium in HMPA/THF.
Abstract: The title compound and the related poly(disilanyl)ethylenes were prepared by the reaction of 1,2-bis(bromodimethylsilyl)-1,2-bis(chlorodimethylsilyl)ethylene with trimethylsilyllithium in HMPA/THF. The physical properties of the title compound as well as its molecular structure by X-ray diffraction are described.
3 citations
TL;DR: Le compose cristallise dans le systeme orthorhombique avec le groupe d'espace Cmca. Affinement de la structure jusqu'a 0,0637 as discussed by the authors.
Abstract: Le compose cristallise dans le systeme orthorhombique avec le groupe d'espace Cmca. Affinement de la structure jusqu'a 0,0637
3 citations
TL;DR: The bridged, pentacyclic intermediate 2 for atisine was synthesized in a naturally occurring enantiomeric form from dimethyl cyclohexanone-2,6-dicarboxylate (6) as discussed by the authors.
Abstract: The bridged, pentacyclic intermediate 2 for atisine (1) was synthesized in a naturally occurring enantiomeric form from dimethyl cyclohexanone-2,6-dicarboxylate (6). The synthesis is composed of the following key steps: (1) formation of the azabicyclo [3.3.1] nonane by a double Mannich reaction, (2) enantioselective conversion by a lipase-catalyzed acylation, (3) stereoselective hydroboration in the presence of BF 3 .Et 2 O, and (4) construction of the bicyclo [2.2.2] octane ring system by an intramolecular double Michael reaction
1 citations
TL;DR: New cyclic polysulfides were directly synthesized by nucleophilic substitution of 1,4-dialkyl-2,3,5,6-tetrahalobenzenes (1 ) with elemental sulfur in liquid ammonia as mentioned in this paper.
Abstract: New cyclic polysulfides, 4,8-dialkylbenzo[1,2-d;4,5-d′]bis[1,2,3]-trithioles ( 2 ) and 6,10-dialkyl[1,2,3]trithiolo[5,4-h]benzopentathiepins ( 3 ), were directly synthesized by nucleophilic substitution of 1,4-dialkyl-2,3,5,6-tetrahalobenzenes ( 1 ) with elemental sulfur in liquid ammonia.