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1.
Reduction of the indole-1-carboxaldehydes (-) with borane /THF gives the 1-methylindoles () in 42-91-% yields together with the di(indolylmethyl)ethers (), the indolyl-methyl indolines (), the unsymmetric ether() and the indolenine () as the minor products, except . This appears to be the first report on the formation of symmetric ethers in the borane/THF reduction of an oxygen function. The formation of and from and implies that electrophilic substitution takes place primarily at position 3 of 3-substituted indoles, did not form the corresponding probably because of steric hindrance. These results are discussed in relation to the mechanisms of borane/THF reduction, origin of the different products and electrophilic substitution in 3-substituted indoles. 相似文献
2.
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
3.
The title intermediate () is produced on photolysis of hexakis(2,6-diethyl-phenyl)cyclotrigermane () or bis(2,6-diethylphenyl)bis(trimethylsilyl)germane () as evidenced by trapping experiments, and thermally dimerizes to tetrakis(2,6-diethyl-phenyl)digermene (). Diarylgermylenes such as do not form stable triethylamine adducts (e.g. ) as has been previously reported. 相似文献
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Maurizio Botta Francesco De Angelis Gabriella Finizia Rosario Nicoletti Maurizio Delfini 《Tetrahedron letters》1985,26(28):3345-3348
Transformation of 6- and 5,6-dialkyl-2-methoxy-4(3H)-pyrimidinones (1a and 1b) into 1--acylated-pyrimidine derivatives 3(-) under Friedel-Craft like conditions is presented. In different acylation conditions 4-O-acylated-pyrimidines (5a and 5b) are also obtained. Compounds (3c) and (3f) can be directly converted into 1--acyl-protected-isouridine analogues (8a and 8b). 相似文献
6.
Epimestranol () is obtained in 80% yield from mestranol () by converting into its methanesulfonate and treating with silver(I) nitrate in a mixture of tetrahydrofuran and water. 相似文献
7.
Takehiko Nishio Katsuhiro Katahira Akira Kato Choji Kashima Yoshimori Omote 《Tetrahedron letters》1979,20(43):4211-4212
Irradiation of N-aryl-2(1H)-pyrimidin-2-ones (-) in a mixed benzene-alcohol solution afforded the products initiated by Type I cleavage, 1-(3-alkoxycarbonylamino-2-propene)-N-arylimines (-, , and ) in 45–51% yields. 相似文献
8.
In a synthetic approach to macrostomine , both side chains of the isoquinoline nucleus are attached by high yield carbon carbon bond formation with lithiated nitrosamines ( → , → ). 相似文献
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A novel approach to (±)-epipodophyllotoxin () and hence also (±)-podophyllotoxin () is described, involving as a key-step the stereoselective ring closure of the TMS-ester derived from to the tetralin derivative with mesyl chloride. 相似文献
11.
C-Glycosides are stereoselectively formed by the titan-(IV)-catalysed addition of silyl enolethers to 2,4,6-tri-O-acyl-1-deoxy-D-erythro-hex-1-enopyran-3-uloses followed by elimination of the 4-acyloxy substituent. Cyclohexenyl silylether reacts with 2-acetoxy-3-keto-glycal derivative forming only one product . Thus, the reaction seems to be diastereospecific with respect to both new chiral centers of the product. 相似文献
12.
Uwe Keppeler Otto Schneider Werner Stöffler Michael Hanack 《Tetrahedron letters》1984,25(34):3679-3682
Conductivity of doped (μ-1,4-diisocyanobenzene)phthalocyaninatoiron(II)-compounds. - The (μ-1,4-diisocyanobenzene)phthalocyaninatoiron(II)-compounds , , and are doped with iodine leading to air stable powders which are stable up to 100°C. They were characterized by elemental analyses, TGA/DTA, IR-, resonance Raman- and 57Fe-Mössbauer spectroscopy. Increasing dopant levels result in higher electronic conductivities up to 10?2 S/cm and in decreasing activation energies. 相似文献
13.
The cationic cyclization of the carbinol (Z) occurred stereoselectively and resulted in a mixture of the hydrindane and the octalin , both with configuration of side chain and angular methyl group. Cyclization of (E) yielded in and , both with -configuration. The structure of , was proved by transformation to the diketones ,. 相似文献
14.
(±)-Isoagatholactone and (±)-12α-hydroxyspongia-13(16),14-dien , a fundamental skeleton of spongiadiol and its congeners, have been synthesized from (±)-labda-8(20),13-dien-15-oic acid . 相似文献
15.
Mikio Hori Tadashi Kataoka Hiroshi Shimizu Akihiko Tomoto 《Tetrahedron letters》1981,22(37):3629-3632
1-Benzoyl-2-methy1-3,4-dihydro-2-thianaphthalene () underwent novel intermolecular 1,4-rearrangement in refluxing toluene to give an enol ether , while rearrangement of 2-phenyl derivative proceeded intramolecularly in refluxing xylene to afford a 1,4-rearranged enol ether . On the other hand, ylides were refluxed in alcohols to afford some ring-opened products . 相似文献
16.
The diene reacted with CHCl3/aq. NaOH/PTC in CH2 Cl2 unexpectedly to give a mixture of the chlorination products and . Usual chlorination with Cl2 yielded similarly , , and dependent on the amount of Cl2. The formation of as well as the reaction of to give (besides ) shows an unusual Cl-Cl-interaction. 相似文献
17.
Stereospecific aldol condensation of at the bridge-head position with i-butyraldehyde gave and in a ratio of 4:1. Using the aldehyde the chiral centers were controlled to produce , in a ratio of 9:3:3:1. Deprotection of the major isomer afforded (±)-N,N′,O-trimethylbicyclomycin . 相似文献
18.
A short route to the 2-azabicyclo[3.3.1]nonan-7-one system is described. Condensation of 4-piperidones with diethyl 2-oxopropylphosphonate, followed by catalytic hydrogenation furnished the corresponding piperidylpropanones which were cyclized with mercuric acetate in acetic acid to the target target bicyclic ketones . The Fischer indole synthesis from afforded regioselectively the indole [3,2-f]morphan , a new heteromorphan type. 相似文献
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《Tetrahedron letters》1987,28(20):2299-2300