Total synthesis of prenylated acylphloroglucinols: faberiones A, B, and E

Abstract

The first total synthesis of acylphloroglucinol-based natural products faberiones A, B, and E is reported, which were isolated from Hypericum faberi. Total syntheses of faberiones A and B are accomplished in six linear steps from commercially accessible 1,3,5-trimethoxybenzene (methyl protected form of phloroglucinol) in overall yields of 31 and 33% respectively, via simple and straightforward approaches that include acylation, omethoxy deprotection, selective iodination and tandem-Sonogashira cyclization followed by C-geranylation. Faberione E is achieved in two linear steps from acylphloroglucinol with an overall yield of 57% via geranylation followed by benzopyran formation reaction.