Zobrazeno 1 - 10
of 62
pro vyhledávání: '"H. Jongejan"'
Publikováno v:
Clinical Nutrition. 36:S104-S105
Autor:
H. C. Van Der Plas, H. Jongejan
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 89:680-686
4,6-Diethoxy-, 4-ethoxy-6-hydrazino-, 4,6-dichloro-, 4,6-di(methylthio)-and 4,6-dihydrazinopyrimidine react with aqueous hydrazine at 210° to give 3-methyl-1,2,4-triazole. Evidence is presented that in this unprecedented ring contraction reaction th
Publikováno v:
Recueil des travaux chimiques des Pays-Bas = Journal of the Royal Netherlands Chemical Society, 102, 364-367
Recueil des travaux chimiques des Pays-Bas = Journal of the Royal Netherlands Chemical Society 102 (1983)
Recueil des travaux chimiques des Pays-Bas = Journal of the Royal Netherlands Chemical Society 102 (1983)
Photolysis of 4-R-1,4(or 3,4)-dihydropyrimidines causes ring contraction into imidazoles, provided that the substituent R is capable of sufficiently stabilizing an anionic centre (R = 2-thiazolyl, 2-pyridyl, 4-pyridyl). Chemical evidence is presented
Autor:
H. C. Van Der Plas, H. Jongejan
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 87:1065-1072
Investigations on ring contraction of pyrimidine and some of its homologues into pyrazoles have been extended. When pyrimidine, 4-methyl- and 4,6-dimethylpyrimidine are allowed to react with hydrazine, pyrazole, 3(=5)-methylpyrazole and 3,5-dimethyl-
Publikováno v:
Tetrahedron Letters, 12, 42, 5521-5524
Tetrahedron Letters, 42, 5521-5524
Tetrahedron Letters 42 (2001)
Tetrahedron Letters, 42, 5521-5524
Tetrahedron Letters 42 (2001)
When HgCl2 was added to a diastereomeric mixture of cis- and trans-(4S)-limonene 1,2-epoxide, the Hg(II) ions stereoselectively complexed to the cis epoxide, enabling ring opening by water. The resulting mercuric salt could be demetalated by treatmen
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 93:225-227
When pyrimidine, 1-methylpyrimidinium methosulfate, 1,3-diethylpyrimidinium tetrafluoroborate or pyrimidine N-oxide is reacted with hydroxylamine hydrochloride, isoxazole is formed in a good yield. On reaction of 4,6-dimethylpyrimidine and its corres
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 95:209-211
On treatment of the quaternary pyrimidinium salts i.e. 1-methyl-4-phenylpyrimidinium iodide and 1-methyl-5-phenylpyrimidinium iodide with cyanamide, O-methylisouronium chloride or bis[S-methylisothiouronium] sulfate in basic media, 2-amino-4-phenylpy
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 90:1246-1248
Pyrimidine is converted by heating with aqueous methylamine or ammonia at 190° into 5-ethyl-2-methylpyridine (5-10%).
Publikováno v:
Tetrahedron Letters, 39, 8345-8348
Tetrahedron Letters 39 (1998)
Tetrahedron Letters 39 (1998)
The pivaloyloxymethyl and butanoyloxymethyl derivatives of tert -butanol and linalool ( 1, 4 ) are readily accepted by hydrolases. Linalool derivative 4b is alcoholysed stereoselectively by Candida rugosa lipase (E=9.7).
Autor:
Paulo M.A.C. Boavida dos Santos, Nuno L.F.L. Camacho Mondril, Aede de Groot, Maurice C. R. Franssen, Anthony L. Spek, Huub Kooijman, H. Jongejan
Publikováno v:
Tetrahedron: Asymmetry 7 (1996)
Tetrahedron: Asymmetry, 7, 497-510
Tetrahedron: Asymmetry, 7, 497-510
Crude lipase from Candida rugosa (CRL) is able to resolve the C3-stereoisomers of the furo[2,3b]furan building block methyl 2-methoxytetrahydrofuran-3-carboxylate 6 by alcoholysis using n -butanol in octane. The reaction is not affected by the config