Total Synthesis of (±)-Cassumunins A–C and Curcumin Analogues

Abstract

A full account of the total synthesis of (±)-cassumunins A–C – superior antioxidants and anti-inflammatory agents – is given. Two novel approaches were developed for synthesizing cassumunins. The total synthesis of cassumunins A and B was accomplished in five linear steps from a known aldehyde in good overall yields of 50 and 43%, respectively, featuring a cascade [3,3]-sigmatropic shift (the Claisen rearrangement) and Heck cross-coupling reaction. Consequently, the total synthesis of cassumunin C was accomplished in three linear steps from a known alcohol with an overall yield of 53%. The key features involved in this synthesis are tandem [3,3]-sigmatropic shift, SN2′ reaction, and aldol condensation. Moreover, a total of eighteen symmetrical and unsymmetrical curcumin analogues were synthesized.