New Convenient Synthesis of Homoisoflavanones and (±)‐Di‐O‐methyldihydroeucomin

Abstract

Upon reaction of 1‐(2‐hydroxyphenyl)‐3‐phenylpropane‐1‐ones (2′‐hydroxy‐dihydrochalcones) with dimethylaminodimethoxymethane in boiling toluene, the corresponding 3‐benzylchromones are obtained in excellent yields. These latter lead to 3‐benzylchroman‐4‐ones (homoisoflavanones) by catalytic hydrogenetion. These reactions were applied to the synthesis of (±)‐3‐benzylchroman‐4‐one and (±)‐3‐(4‐methoxybenzyl)‐5,7‐dimethoxychroman‐4‐one, (±)‐di‐O‐methyldihydroeucomin.

Keywords:

• 3‐Benzylchromones
• homoisoflavanones
• (±)‐di‐O‐methyldihydroeucomin

Acknowledgments

We acknowledge our gratitude to Professor Ch. Tamm for the gift of a reference sample of (±)‐di‐O‐methyldihydroeucomin.