Total synthesis of a demethoxy-egonol from Styrax obassia.

The total synthesis of a demethoxy-egonol isolated from Styrax obassia, 5-(3-hydroxypropyl)-2-(3',4'-methylenedioxyphenyl)benzofuran (9), is described. The key steps involve the construction of a 2-arylbenzofuran skeleton 7 from methyl 3-(4-hydroxyphenyl)propionate with 2-chloro-2-methylthio-(3',4'-methylenedioxy)acetophenone (6) in the presence of ZnCl2 and successive desulfurization of the resulting product 7.