A gem‐Dibromocyclopropane Ring‐Expansion/Mizoroki‐Heck Cyclisation Route to Tetrahydrodibenzofurans

Abstract

AbstractReadily accessible, oxygenated 6,6‐dibromobicyclo[3.1.0]hexanes react with isovanillin in the presence of silver salts and an inorganic base to afford ring‐expanded/nucleophilic trapping products of various regio‐ and stereo‐chemical forms. Most such products undergo efficient, intramolecular Mizoroki‐Heck reactions to give the corresponding tetrahydrodibenzofurans. In certain cases, simple variations in the first step of such reaction sequences enables the preparation distinct ring‐expansion products that also cyclise to give tetrahydrodibenzofurans embodying alternative substitution patterns.