Synthesis ofα-aryloxy cinnamic acids

Abstract

The Perkin-Oglialoro reaction was used for the synthesis of α-aryloxycinnamic acids, but the yields were very low. The potassium tertiary butoxide catalysed condensation of aryloxyacetic ester and aldehydes leads to the formation ofα-aryloxycinnamic acids and its corresponding ester, in good yields through an “oxocyclic intermediate pathway”. The sodium ethoxide catalysed condensation however yields only the esters through an “aldol pathway”, which on saponification give α-aryloxycinnamic acids. These alternative synthetic approaches to Perkin-Oglialoro reaction products, afford excellent methods for the synthesis of α-aryloxycinnamic acids.