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1.
Two steroids, 3-oxo-chol-4-ene-24-oic acid () andi ts unsaturated analog have been isolated from the dorid nudibranch , and the acid has been shown to have antifeedant properties. 相似文献
2.
Toshihiro Hashimoto Motoo Tori Zenei Taira Yoshinori Asakawa 《Tetrahedron letters》1985,26(52):6473-6476
Four novel fusicoccane diterpenoids, fusicoplagins A, B, C, and D, have been isolated from the liverwort subsp. and the structures determined by spectroscopic methods, chemical transformations, and X-ray crystallographic analysis. 相似文献
3.
N-Acyl derivatives of ,-acosamine and ,-ristosamine were synthesized with high stereo selectivity utilizing intramolecular Michael addition of γ- and δ-carbomoyloxy-α,β-unsaturated esters. 相似文献
4.
The 1H and 13C nmr spectra of , -9-oxobicyclo[3.3.1]nonane-2,4-dicarboxylic acid, 3, in DMSO-d6 or alkaline D2O, clearly show that it exists in a --conformation with carboxyl groups, thus being the first case of - preference of a bicyclo[3.3.1] nonan-9-one due to the presence of ,-2,4- substituents. 相似文献
5.
Teruhiko Yoshihara Satoshi Togiya Hiroyuki Koshino Sadao Sakamura Tadayuki Shimanuki Tohru Sato Akitoshi Tajimi 《Tetrahedron letters》1985,26(45):5551-5554
New fungitoxic sesquiterpenes, chokol A (1), B (2), and C (3), have been isolated from stromata of . Their structures and the relative configuration of 3 have been also elucidated from spectral data. 相似文献
6.
J Leitich 《Tetrahedron letters》1980,21(32):3025-3028
The relative rates of formation of and [2+2]cycloadducts of benzyne to , - and , -1,5-cyclooctadiene, - and -cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described. 相似文献
7.
Tomas Fex 《Tetrahedron letters》1981,22(28):2703-2706
The structures of cytochalasin K, L and M, isolated from the fungus , have been determined by spectroscopic methods, primarily 1H NMR and 13C NMR. 相似文献
8.
The structure of engleromycin isolated from Hennings has been established as by spectral techniques. 相似文献
9.
Hans Achenbach Andreas Mühlenfeld Benno Weber G.U. Brillinger 《Tetrahedron letters》1982,23(45):4659-4660
The new compounds – and have been isolated from cultures of 相似文献
10.
A stereOselective conversion of 1,8- and 1,5-diethoxy-9,10-anthraquinone to 1,8- and 1,5-diketo----perhydroanthracenes by successive sodium borohydride, metal-ammonia, and catalytic reductions is described. 相似文献
11.
Giovanni Fronza Claudio Fuganti Piero Grasselli Giulio Marinoni 《Tetrahedron letters》1979,20(40):3883-3886
The enantiomeric alcohols () and (), obtained from (2,3) tartaric acid and, respectively, -threonine, have been used to construct the C6, enantiomeric deoxy amino sugar derivatives () and () 相似文献
12.
The amino acid tyrosine has been shown to be the specific precursor of the isonitrile acid produced by (Bon.) Bain. aggr. 相似文献
13.
Richard R. Izac Steven E. Poet William Fenical Donna Van Engen Jon Clardy 《Tetrahedron letters》1982,23(37):3743-3746
An ichthyotoxic sesquiterpenoid of unusual structure, pacifigorgiol, has been isolated from the Pacific gorgonian caora . The structure of pacifigorgiol, with relative stereochemistry only, has been defined by a combination of spectral and x-ray crystallographic techniques. 相似文献
14.
A range of conjugated ,-dienes have been prepared in a stereo-specific manner acetylene carbocupration: the value of this procedure has been illustrated by an extremely short synthesis of hexadeca-11, 13-dienal a principle component of Navel Orangeworm Pheromone. 相似文献
15.
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
16.
Nobuyasu Enoki Ryoichi Ishida Shiro Urano Takeshi Matsumoto 《Tetrahedron letters》1985,26(14):1731-1734
The structures , , and have been proposed for three new diterpenes from mainly on the basis of spectroscopic evidence. 相似文献
17.
Charles J. Simmons Franz-Josef Marner John H. Cardellina Richard E. Moore Karl Seff 《Tetrahedron letters》1979,20(22):2003-2006
The crystal structure of pukeleimide C, a novel pyrrolic compound from a shallow-water variety of the marine blue-green alga , is reported. 相似文献
18.
Claudio Fuganti Piero Grasselli Giuseppe Pedrocchi-Fantoni 《Tetrahedron letters》1981,22(40):4017-4020
The synthesis of N-benzoyl--daunosamine (14) from the C4 aldehyde (2b), prepared from -threonine, through the intermediacy of the C7 adduct (7a) is reported 相似文献
19.
G. Cimino S. De Stefano L. Minale R. Riccio K. Hirtosu J. Clardy 《Tetrahedron letters》1979,20(38):3619-3622
The structures of two unique sesterpenes, toxislylide A and B, have been deduced by chemical, spectral, and x-ray crystallographic studies. They are components of the sponge . 相似文献
20.
Treatment of halo--methylphosphonium salts with potassium fluoride and halogen (I2, Br2, ICl, IBr) gives modest yields of halo--methanes. This method of preparation augments the classical Hunsdiecker approach to these materials. 相似文献