Resumen
A new synthesis of the natural carbazoles Murrayanine (1) and Murrayafoline A (3) is described. The key step in the synthetic route involved the regioselective cycloaddition of the diene 4,5-dimethylene-3-phenyl-1,3- oxazolidin-2-one (4) to acrolein (6) catalyzed by Lewis acids at low temperature. Direct aromatization of the substituted cyclohexene moiety of adduct 7, and further hydrolysis of the 2-oxazolidinone ring, proved to be a more efficient strategy than the opposite synthetic sequence for the preparation of the corresponding arylphenylamines 14 and 18. Palladium-promoted cyclization of the latter furnished the desired carbazoles 1 and 3 in high overall yields.
Idioma original | Inglés |
---|---|
Páginas (desde-hasta) | 2499-2504 |
Número de páginas | 6 |
Publicación | Synthesis (Germany) |
N.º | 15 |
DOI | |
Estado | Publicada - 18 oct. 2004 |