Isolation and synthesis of polyoxygenated dibenzofurans possessing biological activity.

Reports from the past ten years describing the isolation and/or synthesis of bioactive dibenzofurans possessing three or more oxygen-containing substituents are reviewed. Dibenzofuranoquinones are included in the review.

Facile synthesis of N-dialkylaminomethyl-substituted heterocycles.

Iminium ions are generated by treatment of aminals with succinic anhydride. These iminium ions are trapped by heterocycles, giving the corresponding N-dialkylamino-methyl-substituted heterocycles, which are easily separated from the succinic acid monoamide byproducts by means of an aqueous base wash. The heterocyclic products are obtained in good yield and in a high state of purity without need of recrystallization or distillation.