TOTAL SYNTHESIS OF MORACIN-C

Moracin C has been synthesised by the most efficient route to date (10 steps and 12% overall yield). The relatively unexplored acid-induced, intramolecular migration of an acyl group from an ortho phenolic hydr oxy to a benzylic hydroxy is used to synthesise o-hydroxybenzylphospho nium salts containing ester groups. The phosphonium salts are coupled with 3,5-dimethoxybenzoic acid. Intramolecular Wittig reaction then gi ves 2-arylbenzo[b]furans, bearing the key 1',3',5' substitution patter n on the aryl ring. This discovery provides a concise route to polyphe nolic benzo[b]furans that we expect to be of general utility.