نتایج جستجو برای: indene 2 3 pyrrolizidine
تعداد نتایج: 3350140 فیلتر نتایج به سال:
In each of the two independent indene-4-spiro-pentane mol-ecules in the asymmetric unit of the title 2:1 adduct, C(19)H(18)N(6)·0.5C(5)H(4)OS, the cyclo-hexene ring adopts a half-chair conformation and the cyclo-pentene and cyclo-pentane rings adopt envelope conformations. The mean plane through the cyclo-hexene/cyclo-pentene fused system is aligned at a dihedral angle of 77.9 (1)° with respect...
Propargylic sulfides and dithioacetals are found to undergo similar transformations as propargylic carboxylates when catalyzed by AuCl or AuCl3, affording indene derivatives through pentannulation of aromatic rings. The reaction presumably involves Au carbene as the reactive intermediate.
Abstract We present laboratory rotational spectroscopy of five isomers cyanoindene (2-, 4-, 5-, 6-, and 7-cyanoindene) using a cavity Fourier transform microwave spectrometer operating between 6 40 GHz. Based on these measurements, we report the detection 2-cyanoindene (1H-indene-2-carbonitrile; 2- <mml:math xmlns:mml="http://www.w3.org/1998/M...
The activation of π-bonds in diynyl esters has been investigated by using soft and hard Lewis acids. In the case of the soft selenium Lewis acid PhSeCl, sequential activation of the alkyne bonds leads initially to an isocoumarin (1 equiv PhSeCl) and then to a tetracyclic conjugated structure with the isocoumarin subunit fused to a benzoselenopyran (3 equiv PhSeCl). Conversely, the reaction with...
The versatile synthons 2-chloro-N-(4-sulfamoylphenyl)acetamides la,b were used as a key intermediates for the synthesis of sulfonamide derivatives with adamantyl 2, indene 3, morpholinophenyl 4, pipronyl 5, benzothiazole 6-8, pyrazole 9, thiadiazole 10,11, quinoline 12, isoquinoline 13, thiazoles 14-19, acrylamides 20-24 and benzochromene 25 moieties via reaction with several nitrogen nucleophi...
Investigation of the pyrrolizidine alkaloids of Heliotropium arbainense resulted in the isolation and identification of heliotrine, europine and 7-angelylheliotrine. From H. ovalifolium three alkaloids were isolated: supinine, 7-angelylheliotridine and an alkaloid which was shown to be of the heliotridine monoester type with a dehydrated viridifloric acid.
A diastereoselective and modular approach to the synthesis of the 3-hydroxymethyl-2,3,5,6,7,7a-hexahydro-1H-pyrrolizine-1,2,7-triol structure, characteristic of several natural pyrrolizidine natural products, has been developed. This approach culminated in the synthesis of (-)-7-epiaustraline and (+)-1,7-diepiaustraline. The oxazolidinone group has been found to be a useful protecting group in ...
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