A 10 A simple synthesis of the pentacyclic lamellarin skeleton from 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1-methyl(benzyl)-3,4-dihydroisoquinolines / V. Yu. Korotaev, V. Ya. Sosnovskikh, A. Yu. Barkov, P. A. Slepukhin, M. A. Ezhikova, M. I. Kodess, Yu. V. Shklyaev // Tetrahedron. - 2011. - Vol. 67, № 45. - С. 8685-8698 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): LAMELLARIN ALKALOIDS -- ISOQUINOLINE DERIVATIVES -- HETEROCYCLIC SYSTEM Аннотация: The basic structural framework of lamellarin alkaloids, 8,9-dihydro-6H-chromeno[4?,3?:4,5]pyrrolo[2,1-a]isoquinoline derivatives, has been obtained in good yields via Grob synthesis between 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1-methyl-3,4-dihydroisoquinolines in refluxing isobutanol. In the case of 1-benzyl-3,4-dihydroisoquinolines, a dynamic NMR effect was observed in the 1H and 19F NMR spectra of the products as a result of restricted rotation about the single bond linking the benzene ring and the heterocyclic system. When the reaction was carried out with 3-nitro-2-(trichloromethyl)-2H-chromenes in toluene at room temperature, only Michael adducts, as a mixture of two diastereomers, were isolated.??????--------------------------------------------------------------------------------?? |