Zobrazeno 1 - 10
of 42
pro vyhledávání: '"Toshihiro Kumazawa"'
Publikováno v:
Carbohydrate research. 448
In the synthesis of the main yellow pigment hydroxysafflor yellow A (HSYA), that is present in safflower petals, the key compound 4-(S)-2-acetyl-4,6-di-C-(per-O-acetyl-β-D-glucosyl)-3,4-dihydroxy-5-methoxycyclohexa-2,5-dienone (11b) was diastereosel
Publikováno v:
Journal of Carbohydrate Chemistry. 27:86-102
Refluxing of diacetylphloroglucinol C‐β‐D‐gluco‐, ‐galacto‐, and ‐allopyranosides in water for 1 d gave two kinds of spiroketal derivatives in total yields of 77%, 74%, and 64%, respectively. The structure and stereochemistry of the si
Publikováno v:
Carbohydrate Research. 341:1091-1095
Genistein and orobol 8-C-beta-D-glucopyranosides (1 and 3) were firstly synthesized in overall yields of 39% and 41% from 2,4-di-O-benzylphloroacetophenone (4), as follows: (1) the formation of the chalcone (6, 7) by aldol condensation of the benzyl-
Autor:
Takaharu Kasai, Tohru Suda, Heitaro Obara, Toshihiro Kumazawa, Shingo Sato, Takashi Kusakari, Jun-ichi Onodera
Publikováno v:
Tetrahedron. 61:9630-9636
The synthesis of analogs ( 8 , 12 , 14 ) of two yellow pigments, safflower yellow B and the precursor of carthamin, and carthamin itself, a red pigment, which are produced in safflower ( Carthamus tinctrious L.) petals and, which have a common dimeri
Autor:
Shingo Sato, Shigeru Matsuba, Jun-ichi Onodera, Miho Nemoto, Hitoshi Kamada, Toshihiro Kumazawa, Heitaro Obara, Masaaki Aoyama
Publikováno v:
Carbohydrate Research. 339:2425-2432
N1-Acetoxy-2,2,6,6-tetramethylpiperidin-4-yl 2,3,4,6-tetra-O-benzyl-alpha- and -beta-D-glucopyranosides (3-alpha, beta) and N1-acetoxy-2,2,5,5-tetramethylpyrrolin-3-oyl 2,3,4,6-tetra-O-benzyl-alpha- and -beta-D-glucopyranosylamines (9-alpha, beta) we
Autor:
Kanako Onda, Shingo Sato, Shigeru Matsuba, Jun-ichi Onodera, Hayato Okuyama, Toshihiro Kumazawa
Publikováno v:
Carbohydrate Research. 337:1007-1013
The reaction of 2,3,4-tri-O-benzyl-6-deoxy-alpha-D-glucopyranosyl fluoride, 2,3,4,6-tetra-O-benzyl-alpha-D-allopyranosyl fluoride, and 2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl fluoride with 2,4-di-O-benzylphloroacetophenone, in the presence of boron
Autor:
Heitaro Obara, Hitoshi Kamada, Masaaki Aoyama, Shingo Sato, Toshihiro Kumazawa, Jun-ichi Onodera, Shigeru Matsuba
Publikováno v:
Carbohydrate Research. 334:215-222
Glycosylation of the nitroxyl radicals, 4-acetoxy-2,2,6,6-tetramethylpiperidin-1-oxyl (4-acetoxy-TEMPO) and 3-carbamoyl-2,2,5,5-tetramethylpyrollin-1-oxyl (3-carbamoyl-PROXYL) with peracetylglycosyl fluoride as the glycosyl donor, in the presence of
Publikováno v:
Carbohydrate Research. 329:507-513
Isoorientin, a 6-C-β- d -glucopyranosyl-3′,4′,5,7-tetrahydroxyflavone, was synthesized in a 15% overall yield, in ten steps, starting from the commercially available phloroacetophenone. The C-glucosyl phloroacetophenone derivative, a synthetic i
Autor:
Hironobu Kumagai, Nobuo Kitamura, Shigeru Matsuba, Jun-ichi Onodera, Shingo Sato, Toshihiro Kumazawa, Masanobu Suzuki, Takeshi Watanabe
Publikováno v:
Journal of Heterocyclic Chemistry. 36:1189-1193
Condensation of 2-hydroxyacetophenone with benzaldehyde in the presence of 70% perchloric acid in ethyl orthoformate gave the corresponding 4-ethoxyflavylium perchlorate, which was treated with aqueous ammonia or methylamine solution to afford 1,6,7,
Publikováno v:
Carbohydrate Research. 320:129-137
2′- O -Acetyl C -glycosylic compounds ( C -glycosides) were prepared via regioselective acetyl transfer from aglycons to sugar moieties with silica gel in the presence of unprotected primary and secondary hydroxyl groups.