排序方式: 共有26条查询结果,搜索用时 395 毫秒
21.
Hidetoshi Yamada Kotaro Okajima Tatsuya Mukae Mugio Nishizawa 《Tetrahedron letters》2004,45(15):3157-3160
The ring-conformational change of myo-inositol derivatives by introducing two tert-butyldimethylsilyl, triisopropylsilyl, or tert-butyldiphenylsilyl groups into the 1,2-trans hydroxy groups--3,4- and 4,5-positions--were investigated. The cyclohexane cores of the 4,5-bis-O-silylated derivatives with tert-butyldiphenylsilyl or triisopropylsilyl groups were present in the axial-rich chair form. 相似文献
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Hidetoshi Yamada Koki Tanigakiuchi Kohei Nagao Kotaro Okajima Tatsuya Mukae 《Tetrahedron letters》2004,45(29):5615-5618
The ring conformations of 3,4-bis-O-tert-butyldimethylsilyl- and 3,4-bis-O-tert-butyldiphenylsilyl-d-glucopyranoses as well as the corresponding phenyl 1-thio-d-glucopyranosides were investigated. Observations showed that the introduction of the two tert-butyldiphenylsilyl groups can flip the pyranose-ring into the 1C4 conformation possessing more axial substituents. All the substituents of the 3,4-bis-O-tert-butyldiphenylsilyl-β-d-glucopyranose were axially oriented. 相似文献
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Hidetoshi Yamada Koki Tanigakiuchi Kohei Nagao Kotaro Okajima Tatsuya Mukae 《Tetrahedron letters》2004,45(50):9207-9209
The pyranose rings of the 2,3-bis-O-tert-butyldiphenylsilyl-α- and β-d-glucopyranoses, and of the 2,3-bis-O-tert-butyldimethylsilyl-β-d-glucopyranose were in the 1C4 form. These findings indicate that the introduction of bulky silyl protecting groups at the 2- and 3-positions can flip a pyranose ring into the axial-rich chair form. Previous such ring inversions have been carried out by the silyl protections at the 3- and 4-positions. 相似文献
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Raiji Mukae Atsuhiro Nakamoto Yoshiaki Oda Yusuke Suzuki 《Graphs and Combinatorics》2010,26(4):559-570
In this paper, we shall give a constructive characterization of triangulations on the nonorientable surface of genus 3 without K 6-minors. Our characterization implies that every 5-connected triangulation and every 4-representative triangulation on the surface has a K 6-minor. 相似文献
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Masahiro Yoshida Miki Shibata Saaya Mukae Kouki Kinoshita Kenji Matsumoto Tsukasa Hirokane 《Tetrahedron letters》2019,60(49):151262
Cyclization of 4-hydroxy-2-pyrones with allylic bisacetates by a palladium catalyst is described. Pyrone-annulated 2-oxabicyclo[3.3.1]nonane derivatives were regioselectively produced from the reaction of 4-hydroxy-2-pyrones with 1,4-diacetoxy-2-cyclohexene at high temperature. The reaction would proceed via a migration of the π-allylpalladium intermediate. 相似文献