RESUMO
This article reports the synthesis of spiro compounds based on an indanedione-cyclopropane-pyrazolone framework. The reaction relied upon the Michael-initiated ring closure strategy and was carried out under Cu(OAc)2 catalysis, assisted by an oxygen atmosphere and the base Et3N. The final compounds were obtained as an inseparable mixture in most cases with modest to good yields using diverse substrates. Among the two plausible routes, computational studies indicated the feasibility of a route which involves a four-membered Cu containing intermediate. Given the generic nature of the developed method, it may be utilised to synthesise other analogous spiro systems.
Assuntos
Cobre , Compostos de Espiro , Acetatos , Catálise , Cobre/química , Indanos , Estrutura Molecular , Compostos de Espiro/químicaRESUMO
This paper describes the synthesis of two distinct types of CF3-containing spirooxindoles by varying the active methylene sources. The reaction was carried out in DMSO, assisted by molecular iodine and Na2CO3via systematic application of Michael reaction and iodine mediated cyclisation. With 5-methyl-2,4-dihydro-3H-pyrazol-3-one as the methylene source, the final products obtained were spirodihydrofuropyrazolyl oxindoles, whereas 1H-indene-1,3(2H)-dione as the methylene source gave the final compounds spirocyclopropyl oxindoles. Modest to good yields were obtained for both the spiro systems.
RESUMO
The first total synthesis of racemic microthecaline A, a quinoline serrulatane alkaloid, isolated from the Australian desert plant Eremophila microtheca is described. The natural product was synthesized in ten steps, starting from ethyl 4-bromo-6-methoxy-8-methylquinoline-3-carboxylate in 8% overall yield.