Síntese de 1,3-diarilpropanos

Abstract

This work describes the synthesis of three 1,3-diarylpropanes: 1-(2'-hydroxy-4'-methoxyphenyl)-3-(3"-hydroxy-4"-methoxyphenyl)-propane,1-(2',4'-dihydroxy-3',5'-dimethylphenyl)-3-(2"-hydroxy-4",5"-methylenedioxyphenyl)-propane and 1-(2'-hydroxy-5'-methyl-4'-methoxyphenyl)-3-(2"-hydroxy-4",5"-methylenedioxyphenyl)-propane. These compounds were synthesized with the purpose of confirming the proposed structures for the natural 1,3-diarylpropanes extracted from Virola multinervia, Iryanthera coriaceae and Iryanthera laevis. The synthetic pathway employed in this work involved the preparation of substituted acetophenones and benzaldehydes which, by aldol condensations, afforded the corresponding chalcones. These were submitted to catalytic hydrogenation (Pd-C, 10%) and Clemmensen reduction to give the title compounds which were characterised by I.R., 1H N.M.R. and Mass spectrometry. The comparison between the spectral data of the syntbetic 1,3-diarylpropancs and those of the natural products made it possible to confirm the structures for those compounds extracted from V. multinervia and I. coriaceae. Based on the fact that the spectral data of the synthetic product and those of the natural one obtained from I. laevis are not identical, a new structure is suggested for this 1,3-diaryl propane, namely, 1-(4'-hydroxy-2'-methoxyphenyl-5'-methyl)-3-(2"-hydroxy-4",5"-methylenedioxyphenyl)-propane.