Regioselective Synthesis of 2‐and 3‐Aryl‐1,4‐benzodioxanes

Abstract

Abstract 3‐Aryl‐ and 2‐aryl‐1,4‐benzodioxane derivatives of type 4d and 5d are excellent starting compounds for the synthesis of natural flavano‐ and neolignans. The syntheses of 4d and 5d were achieved with high regioselectivity by oxidative coupling of caffeic acid ethyl ester ( 2h ) and coniferyl alcohol ( 1c ) in the presence of a silver salt (oxide, carbonate) and potassium hexacyanoferrate(III), respectively.