Concise Synthetic Approaches to Naturally Occurring β-Hydroxypyranochalcones: First Total Synthesis of Purpurenone, Its Derivative, and Praecansone B

摘要

The total synthesis of biologically interesting β-hydroxypyranochalcones, purpurenone (1), its derivative 2, praecansone B (3), and pongapinone A (4) has been accomplished starting from commercially available 2,4- dihydroxyacetophenone or 6-methoxy-2,4-dihydroxyacetophenone in 3 steps by a convergent strategy through benzopyran formations, O-methylations, and coupling reactions.