Synthesis of C-Alkyl Calix[4]arenes. 3. Acid-Catalyzed Rearrangement of 2,6-Dimethoxycinnamate Prior to Tetramerization to Calix[4]arenes

In our continuing studies concerning the versatility of the acid-catalyzed conversion of cinnamates to calix[4lresorcinarenes, we have demonstrated that 2,6-dimethoxycinnamic acid ethyl ester 3 undergoes an interesting rearrangement to afford the same calix[4lresorcinarenes as those obtained from the 2,4-dimethoxy isomer 1. The experimental results were substantiated by molecular mechanics calculations