Figure 1: Natural ellagitannins possessing highly oxygenated diaryl ethers.
From: A unified strategy for the synthesis of highly oxygenated diaryl ethers featured in ellagitannins
The parts indicated with bold lines are the highly oxygenated diaryl ethers, C–O digallates. Each common name is also indicated. The C–O digallates allow oligomerization of basic ellagitannins, which is a major factor in conferring structural diversity. However, the methods for synthesizing C–O digallates have been quite limited to date.
