Zobrazeno 1 - 10
of 14
pro vyhledávání: '"Makoto Yamamoto"'
Publikováno v:
Chemistry Letters. 20:1865-1868
Hydrolysis of glycidyl benzoates in the presence of BF3·OEt2 in CH2Cl2 affords regioisomeric triol mono benzoates, their ratios remarkably change depending on the temperature particularly in the reaction of 3,3-dimethylglycidyl benzoate.
Publikováno v:
Chemistry Letters. 20:1457-1460
The first example of intramolecular radical cyclization of ketene radical synthon is presented. Intramolecular radical cyclization of 2-bromo-ketene-S,S-acetals proceeded highly regioselectively to give the corresponding 5-exo-trig cyclized γ-lacton
Publikováno v:
Chemistry Letters. 26:1035-1036
Anti-β-stannyl-α-substituted carbonyl compounds were completely converted to its syn-analogues, and each diastereomer was oxidized to its β-hydroxylated analogues with retention of the stereochemistry.
Publikováno v:
Chemistry Letters. 23:1605-1606
Isolable conformers of 2-alkylamino-N-(2′-alkylphenyl)succinimide were stereoselectively synthesized by amination of N-(2′-alkylphenyl)maleimides. The rotational barrier and the α-methylation of them were investigated.
Autor:
Kentaro Yamaguchi, Katsuya Sakayori, Shigeo Kohmoto, Yasuhiro Noguchi, Makoto Yamamoto, Keiki Kishikawa
Publikováno v:
Scopus-Elsevier
The new type channel structure in the chemistry of cholic acid was created by the protection of both end (the hydroxy group at the 3-position and the carboxy group at the 23-position) of cholic acid. The inhibition of the intermolecular hydrogen bond
Publikováno v:
Chemistry Letters. 19:1123-1124
Hydrochlorination of acryloylureas was attempted using titanium tetrachloride and 2-propanol to give chloroacylureas with high yield and stereoselectivity.
Publikováno v:
Chemistry Letters. 19:1009-1010
The relation between the separability and the stereochemistry of the acylurea derivatives prepared from chiral mono-, bi- and tricyclic acids and N,N′-bis((S)-1-phenylethyl)carbodiimide were investigated. Conventionally separated diastereomers by s
Publikováno v:
Chemistry Letters. 18:787-790
The aldol addition reaction of chiral acetylurea with aldehydes diastereoselectively gives β-alkyl-β-hydroxypropionyl-ureas (3 and 4) and the methanolysis of the adducts 3 and 4, separated perfectly by conventional column chromatography on silica g
Publikováno v:
Chemistry Letters. 17:1477-1478
The reaction of bicyclic 1,3-diene 1,4-endoperoxides with SnCl2 re-generated the corresponding dienes in 15–70% yield. The efficiency of the deoxygenation depended on the structure of peroxides. The results were compared with those of Fe(II) as wel
Publikováno v:
Chemistry Letters. 17:1623-1624
Asymmetric Diels–Alder reaction of the chiral acrylamide 1 proceeds highly diastereoselectively and methanolysis of the adduct 2 gives the optically pure (3R, 4R, 6R)-bicyclo [2. 2. 1]heptene-4-carboxylate.