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.