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1.
Biogenetic-type synthesis of (±)-dictyopterene A () was achieved employing 1,-5-undecadien-3-ol () postulated to be a biosynthetic intermediate of : this synthesis means that transformation of dictyoprolene () into dictyopterene A () was formally made. 相似文献
2.
The synthesis of 2,4-dimethoxypyrrolo[3,2-]pyrimidine () is described. This facile, 3-step synthesis involves the bromination of 2,4-dimethoxy-6-methyl-5-nitropyrimidine (), and the subsequent conversion of compound into compound . 相似文献
3.
An efficient, highly stereoselective synthesis of (1,3)--chrysanthemic acid 6 is described. The crucial step of this synthesis was the microbiological reduction of dione 1 into ()-ketol 2. 相似文献
4.
A new and convenient synthesis of 2-isopropylfuro-(2,3-b)quinolines () from 3-(3-methylbut-1-enyl)-2-quinolones () is described. A neat synthesis of the alkaloids (±)-lunacrine (), (±)-lunasine () and (±)-demethoxylunacrine () is also reported. 相似文献
5.
A short-step synthesis of , the right-hand half of antibiotic saframycin (), is described. The key steps of this synthesis are the acid catalyzed intramolecular double cyclization of and the oxidative demethylation of to the quinone (). 相似文献
6.
Starting from the ketones and the synthesis of six spiro ethers with an l-oxaspiro[4.5]decane skeleton is described. Five of them, ,, , and represent typical partial structures of the sesquiterpenoid spiro ether . The unambiguous synthesis of shows a previous assignment of “'bisabolene oxide“' to structure to be wrong. 相似文献
7.
Chromanmethanol , a chiral intermediate for the synthesis of α-tocopherol , is prepared from α-hydroxy aldehyde , which is obtained by an asymmetric synthesis in over 95% ee. 相似文献
8.
Enrico Mincione Anthony J. Pearson Paolo Bovicelli Malcolm Chandler Geoffrey C. Heywood 《Tetrahedron letters》1981,22(30):2929-2932
New Methodology is described for the synthesis 6-ketosteroids, of potential value for the synthesis of β-ecdysone, tricarbonyl (4-methoxy-1-methylcyclohexadienyl) iron hexafluorophosphate . 相似文献
9.
Regio- and stereoselective methods are described for the synthesis of compounds possessing the stereochemistry of type , , , and from the aldehyde . 相似文献
10.
Non-conjugated -dialkylated alkenes were oxidized to aldehydes in the presence of α,β-unsaturated carbonyl functional groups, providing a new synthesis of and a synthesis of that led to a revised structure for gastrolactone. 相似文献
11.
A novel and efficient partial synthesis of 1α-hydroxy vitamin D3 (), starting from 7-dehydrocholesterol (), is reported. The crucial step in the synthesis involves a selective Diels-Alder reaction of 4-phenyl-1,2,4-triazoline-3,5-dione with the 6,8-diene system of previtamin D3 (), generating an adduct suitable for the stereoselective introduction of the 1α-hydroxyl group. Cycloreversion of leads to the title compound. 相似文献
12.
René Grée Jilali Kessabi Paul Mosset Jacques Martelli Robert Carrié 《Tetrahedron letters》1984,25(34):3697-3700
A stereoselective synthesis of dienes and , using butadiene-iron tricarbonyl complexes, is described. Higher diastereoselectivity is observed during Diels-Alder reaction of as compared with , affording good evidence for cooperativity in these cycloadditions. 相似文献
13.
The stereoselective total synthesis of 2β,3β,20β-triacetoxy-5α-pregnan-6-one () via acetylene-cation cyclization of , which was readily derived from the D-ring aromatic steroid , is described and this constitutes a total synthesis of 20-hydroxyecdysone (). 相似文献
14.
The total synthesis of a 3-thia- and a 3-aza-1-dethiacepham ( and ) are described. Neither compound possessed antibacterial activity . . An unsaturated analog, a 3-aza-1-dethiaceph-1-em exhibited weak antibacterial activity. 相似文献
15.
G. Kunesch P. Zagatti J.Y. Lallemand A. Debal J.P. Vigneron 《Tetrahedron letters》1981,22(52):5270-5274
The structure of the sex attractant isolated from the wing glands of has been determined by chemical and physical methods as -3-methyl-4-dimethylallyl- γ -lactone . The synthesis of racemic is described. 相似文献
16.
Ronald J. Quiann Richard P. Gregson Alan F. Cook Robert T. Bartlett 《Tetrahedron letters》1980,21(6):567-568
A new pharmacologically active agent isolated from the marine sponge has been identified as 1-methylisoguanosine () by spectral and degradative chemical methods and synthesis from a β-D-ribofuranosylimidazole (). 相似文献
17.
The new building blocks , , and have been effecively synthesized starting from 2-hydroxymethyl-4-phenylthio-1-butene (). A convenient synthesis of retinoic acid methyl ester () using is also described. 相似文献
18.
A stereospecific synthesis of acetyl--valyl-detoxininolactone has been performed and the absolute stereochemistry of detoxinine has been revised to (2, 3, 1′)-2-(2′-carboxy-1′-hydroxyethyl)-3-hydroxypyrrolidine. 相似文献
19.
Tadashi Nakata Shigeto Nagao Sachiko Takao Tadasu Tanaka Takeshi Oishi 《Tetrahedron letters》1985,26(1):73-74
(1,3,5)-1,3-Dimethyl]-2,9-dioxabicyclo[3.3.1]nonane has been stereoselectively synthesized based on a highly stereoselective method for the synthesis of 1,3--polyol. 相似文献
20.
Total synthesis of codonocarpine () and its regio-isomer () utilizing a new cyclization procedure is described. 相似文献