Synthesis of rodocaine

A new method for synthesis of rodocaine (1) is presented. Two key steps were carried out by the N-bromosuccinimide (NBS)-mediated intermolecular addition of known enamine 5 with allyltrimethyl silane in presence of boron trifluoride etherate (BF3/OEt2) and the intramolecular ring-closing metathesis of triene 3. The Diels–Alder cycloaddition of triene 3 with different ethyl propiolates was also studied.