Papers - YAMAMURA Hatsuo
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Stereodivergent Allylindation of Cyclopropenes. Remarkable Stereodirection and Aaceleration by Neighbouring Carboxyl and HydroxylGroups Reviewed
Shuki ARAKI, Hiroyuki NAKANO, Kandasamy SUBBURAJ, Syunehisa HIRASHITA, Kensuke SHIBUTANI, Hastuo YAMAMURA, Masao KAWAI, YasuoBUTSUGAN
Tetrahedron Lett 39 6327 - 6330 1998.04
Publishing type：Research paper (scientific journal)
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Stereochemistry of Protected Ornithine Side Chains in Gramicidin D Derivatives and Their Resistance to N-Methylation Reviewed
Masao KAWAI, Tatsuo YAMAMOTO, Keiichi YAMADA, Masashi YAMAGUCHI, Shigehiro KUROBE, Hastuo YAMAMURA, Shuki ARAKI, Yasuo BUTSUGAN,Kyoko KOBAYASHI, Ryoichi KATAKAI, Kazuki SAITO, Terumi NAKAJIMA
Lett. Pept. Sci. 5 5 - 12 1998.04
Publishing type：Research paper (scientific journal)
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Hastuo YAMAMURA, Tadahiro YOTSUYA, Satoshi USAMI, Akihito IWASA, Shoji ONO, Yoshihisa TANABE, Daisuke IIDA, Takao KATSUHARA, KazuakiKANO, Testuo UCHIDA, Shuki ARAKI, Masao KAWAI
J. Chem. Soc., Perkin Trans. 1 1299 - 1303 1998.04
Publishing type：Research paper (scientific journal)
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Keiichi YAMADA, Hirotaka OZAKI, Naoki KANDAa, Hastuo YAMAMURA, Shuki Araki, Masao KAWAI
J. Chem. Soc., Perkin Trans. 1 3999 - 4004 1998.04
Publishing type：Research paper (scientific journal)
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Nitrogen-rich Mesoionic Compounds from 5-Chloro-1,3-diaryltetraazolium Salts and Nitrogen Nucleophiles. Synthesisand Properties of 5-Azido-1,3-diaryltetrazolium Salts Reviewed
Shuki ARAKI, Kaori YAMAMOTO, Misako YAGI, Tomoko INOUE, Hiroyo FUKUNAGA, Hiromi HATTORI, Hastuo YAMAMURA, Masao KAWAI, YasuoBUTSUGAN
Eur. J. Org. Chem. 121 - 127 1998.04
Publishing type：Research paper (scientific journal)
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Primary hydroxy-modified cyclomaltoheptaose derivatives with two kinds of substituents. Preparation of 6(I)-(benzyloxycarbonylamino)-, 6(I)-(tert-butoxycarbonylamino)- and 6(I)-azido-6(I)-deoxy-6(II),6(III),6(IV),6(V),6(VI),6(VII)-hexa-O-tosylcyclomaltoheptaose and their conversion to the hexakis-(3,6-anyhdro) derivatives Reviewed
H Yamamura, T Yotsuya, S Usami, A Iwasa, S Ono, Y Tanabe, D Iida, T Katsuhara, K Kano, T Uchida, S Araki, M Kawai
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1 ( 7 ) 1299 - 1303 1998.04
Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY
Three cyclomaltoheptaoses (1, 2 and 3) which possess a benzyloxycarbonylamino group, a tert-butoxycarbonylamino group or an azido group, and six tosyloxy groups, on their C-6 atoms have been prepared. These can be versatile intermediates for the synthesis of derivatives possessing an amino group as well as other functional groups. As an example of their derivatization, their conversion to compounds containing 3,6-anhydroglucoses, which possess cation-binding abilities, is also reported.
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Stereochemistry of protected ornithine side chains in gramicidin S derivatives and their resistance to N-methylation Reviewed
Masao Kawai, Tatsuo Yamamoto, Keiichi Yamada, Masashi Yamaguchi, Shigehiro Kurobe, Hatsuo Yamamura, Shuki Araki, Yasuo Butsugan, Kyoko Kobayashi, Ryoichi Katakai, Kazuki Saito, Terumi Nakajima
Letters in Peptide Science 5 ( 1 ) 5 - 12 1998
Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Netherlands
Derivatives of gramicidin S (GS) and its mono- and di-D-cyclohexylalanine (D-Cha) analogs possessing various protecting groups on Orn side chains were prepared. 1H NMR spectra of the unsymmetrically protected analogs [Orn(X)2,Orn(X′)2′,D-Cha4]GS were similar to the composites of the spectra of the symmetrical derivatives [Orn(X)2,2′,D-Cha4,4′]GS and [Orn(X′)2,2′]GS, revealing the proximity of the protecting groups of NδH of Orn residues at the 2 and 2′ positions to the side chains of D-Phe (or D-Cha) residues at the 4 and 4′ positions, respectively. The results indicated the presence of H-bonds between the NδH of Orn and the carbonyl of D-Phe residues in the i → i + 2 sense and not in i → i - 3, which was also supported by the ROESY analysis. The substantially strong H-bonds can explain the observed resistance of the urethane NH of the Orn side chains in the GS derivatives to the N-methylation with CH3I-Ag2O in DMF.
DOI： 10.1007/BF02443534
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Selective Reduction of Organic Functional Groups with Indium Hydride Reagents Reviewed
Masafumi YAMADA, Koji TANAKA, Yasuo BUTSUGAN, Masao KAWAI, Hastuo YAMAMURA, Shuki ARAKI
Main Group Metal Chemistry 20 ( 4 ) 241 - 246 1997.04
Language：English Publishing type：Research paper (scientific journal) Publisher：FREUND PUBLISHING HOUSE
New indium hydride reagents LiPhnInHe4-n (n = 0-2) were prepared and their reactivity and selectivity for various organic compounds containing representative functional groups were studied. It was shown that the reactivity can be controlled by changing the substituents and their number on the central indium atom. Their stereoselectivities were comparable to those of sodium borohydride and lithium aluminium hydride.
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High gamma-Selectivity in the Coupling of Penta-2,4-dienyl- and Pent-2-en-4-ynylindium Reagents with Aldehy Reviewed
Tsunehisa HIRASHITA, Shi'ichiro INOUE, Hastuo YAMAMURA, Masao KAWAI, Shuki ARAKI
J. Organometalic Chemistry 549 305 - 309 1997.04
Publishing type：Research paper (scientific journal)
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Diastereoselective Reduction of Acyclic Hydroxyketones and Diketones with an Indium Hydride Reagent Reviewed
Masafumi YAMADA, Tomoaki Horie, Masao KAWAI, Hastuo YAMAMURA, Shuki ARAKI
Tetrahedron 53 15685 - 15690 1997.04
Publishing type：Research paper (scientific journal)
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Convenient Enantioselective Preparation of Salsolinol-1-carboxylic Acid Reviewed
Masao KAWAI, Yulin Deng, Ikuko KIMURA, Hatsuo YAMAMURA, Shuki ARAKI, Makoto NAOI
Tetrahedron: Asymmetry 8 1487 - 1490 1997.04
Publishing type：Research paper (scientific journal)
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Assay for the (R)- and (S)-Enantiomers of Salsolinols in Biological Samples and Foods with Ion-pair High-performance liquidChromatography using beta-Cyclodextrin as a Chiral mobile Phase Additive Reviewed
Yulin Deng, Wakako MARUYAMA, Masao KAWAI, Philippe Dostert, Hatsuo YAMAMURA, Tsutomu TAKAHASHI, Makoto NAOI
J. Chromatography B. 689 313 - 320 1997.04
Publishing type：Research paper (scientific journal)
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Assay for the (R)- and (S)-Enantiomers of Salsolinols in Biological Samples and Foods with Ion-pair High-performance liquidChromatography using beta-Cyclodextrin as a Chiral mobile Phase Additive Reviewed
J. Chromatography B. 689 313 - 320 1997.04
Publishing type：Research paper (scientific journal)
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Selective reduction of organic functional groups with indium hydride reagents Reviewed
Masafumi Yamada, Koji Tanaka, Yasuo Butsugan, Masao Kawai, Hatsuo Yamamura, Shuki Araki
Main Group Metal Chemistry 20 ( 4 ) 241 - 246 1997
Language：English Publishing type：Research paper (scientific journal) Publisher：Walter de Gruyter GmbH
New indium hydride reagents LiPhnInH4-n (n = 0-2) were prepared and their reactivity and selectivity for various organic compounds containing representative functional groups were studied. It was shown that the reactivity can be controlled by changing the substituents and their number on the central indium atom. Their stereoselectivities were comparable to those of sodium borohydride and lithium aluminium hydride.
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Mechanism of enantioseparation of salsolinols, endogenous neurotoxins in human brain, with ion-pair chromatography using beta-cyclodextrin as a mobile phase additive Reviewed
YL Deng, W Maruyama, H Yamamura, M Kawai, P Dostert, M Naoi
ANALYTICAL CHEMISTRY 68 ( 17 ) 2826 - 2831 1996.09
Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC
A novel method for direct separation of the enantiomers of salsolinol and N-methylsalsolinol was devised, The enantiomers were completely separated with ion-pair chromatography on a reversed-phase column with beta-cyclodextrin as a chiral mobile phase additive and sodium 1-heptanesulfonate as a counterion. The mechanism for enantioseparation with this ion-pair system containing a-cyclodextrin was discussed, The effects of beta-cyclodextrin, counterions, pH, ionic strength, and organic solvent on retention were investigated, and a retention model was proposed and proved to be consistent with the experimental data. A preliminary study of the enantiomeric composition of salsolinol and N-methylsalsolinol in banana and in human brain was made as an example of the application of this assay.
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Structural Revision of Physalin H Isolated from Physalis anguluta Reviewed
Bunsho MAKINO, Masao KAWAI, Toichi OGURA, Masaki NAKANISHI, Hatsuo YAMAMURA, Yasuo BUSTUGAN
J. Natural Products 58 1668 - 74 1996.04
Publishing type：Research paper (scientific journal)
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Preparation of Protected alpha-Alkoxyglycines. Reviewed
Masao KAWAI, Kouji HOSODA, Yoshimasa Omori, Keiichi YAMADA, Shiko HAYAKAWA, Hatsuo YAMAMURA, Yasuo BUSTUGAN
Synthetic Communications 26 1545 - 1554 1996.04
Publishing type：Research paper (scientific journal)
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Mechanism of Enantioseparation of Salsolinols, Endogenous Neurotoxins in Human Brain, with Ion-Pair Chromatography Usingbeta-Cyclodextrin as a Mobile Phase Additive. Reviewed
Yulin Deng, Wakako MARUYAMA, Hatsuo YAMAMURA, Masao KAWAI, Philippe Dostert, Makoto NAOI
Anal. Chem. 68 2826 - 2831 1996.04
Publishing type：Research paper (scientific journal)
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Indium-mediated Reaction of 1,3-Dichloro- and 1,3-Dibromopropens with Carbonyl Compounds. Generation of Novel 3,3-Diindiopropene. Reviewed
Shuki ARAKI, Tsunehisa HIRASHITA, Hidetaka SHIMIZU, Hatsuo YAMAMURA, Masao KAWAI, Yasuo BUTSUGAN
Tetrahedron Lett. 37 8417 - 8420 1996.04
Publishing type：Research paper (scientific journal)
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Dependence of Guest-binding Ability on Cavity Shape of Deformed Cyclodextrins. Reviewed
Kahee FUJITA, Yuji OKABE, Kazuko OHTA, Hatsuo YAMAMURA, Tsutomu TAHARA, Yasuyoshi NOGAMI, Toshitaka KOGA
Tetrahedron Lett. 37 1825 - 1828 1996.04
Publishing type：Research paper (scientific journal)
