Oxazolines are five-membered heterocyclic compounds with one double bond. The double bond may be in one of three positions, so there may be three different oxazoline rings. The 2-oxazoline structure is the most common, and 3-oxazoline and 4-oxazoline exist mainly as laboratory research compounds. Oxazolines exist between oxazole and oxazolidine in terms of saturation.
Dibenzofuran is an organic compound (C12H8O) consisting of two benzene rings fused to a central furan ring. Dibenzofuran can be synthesized by annealing and oxidative coupling methods of diphenyl ether, biphenyl derivatives, benzofuran, quinone. Most of the dibenzofuran-related natural products are metabolites of lichens or higher fungi. Lichen dibenzofurans appear to be formed by carbon-carbon oxidative coupling of orsellinic acid and its homologs.