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1.
2-Vinylindoles are obtained from the Fischer indolization of α,β-unsaturated ketones. Heating 2-(2-methylpropenyl)indole (4) with the Vilsmeier reagent (DMF/POCl3) gave 2-methylcarbazole in good yield, presumably an electrocyclic ring closure of a hexatrienic intermediate. 相似文献
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N-Acylaziridines couple efficiently with organolithium and Grignard reagents to produce ketones in high yields. 相似文献
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All four isomers of substituted 3-alkylthio-4-hydroxybutenes have been synthesised: both the geometry of the double bond and the relative stereochemistry of the two chiral centres are controlled. 相似文献
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General methods for inverting the stereochemisty of vinyl -alcohols such as and into and respectively are described. The procedures employ a [2,3] sulfoxide rearrangement and will facilitate the extended use of the oxy-Cope rearrangement to a variety of related ring systems. 相似文献
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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
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Starting from the coupling reaction of alkyl cuprates with 1-alkynyl-2-propenyl acetates, the title compounds were prepared by short convenient syntheses. 相似文献
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The facile decomposition of methyl chlorodifluoroacetate, induced by either lithium chloride/hexamethylphosphoric triamide complex or potassium fluoride/18-Crown-6 complex, has been carried out in the presence of a variety of olefinic substrates to yield the corresponding -difluorocyclopropanes. The ester decomposition has been determined to yield “free” difluorocarbene a three-step process involving an intermediate chlorodifluoromethide ion. 相似文献
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Flow vacuum thermolysis (500–650°) of 1,2-cyclonona- and 1,2-cyclodecadienes yields, as primary products, terminal enynes and enedienes. Secondary intramolecular Diels-Alder reactions of the enedienes afford and bicyclics. 相似文献
16.
Claudio Fuganti Piero Grasselli Stefano Servi Carlo Zirotti 《Tetrahedron letters》1982,23(41):4269-4272
The C4erythro and threo diols (7) and (8) are converted either into the chiral epoxides (13) and (15) or into the enantiomers (14) and (16); the epoxide (13) is used as chiral synthon for the preparation of (3,4) 4-methyl-3-heptanol (21). 相似文献
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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
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Base catalyzed decompositions of 2-(α-ethoxycarbonyl-benzyl)-3-phenyl-oxaziridines carried out in benzene in an atmosphere of oxygen yielded N-benzoyl benzamides along with ethyl phenylglyoxylate imine and benzaldehydes. 相似文献
20.
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