Absolute Configuration of Anti-HIV-1 Agent (−)-Concentricolide: Total Synthesis of (+)-(<i>R</i>)-Concentricolide
作者:Chih-Wei Chang、Rong-Jie Chein
DOI:10.1021/jo2004132
日期:2011.5.20
The first enantioselective total synthesis of (+)-(R)-concentricolide, the enantiomer of an anti-HIV-1 agent isolated from Daldinia concentrica, from 2-iodophenol in 7 steps reveals the (S)-configuration for the natural form of the furanophthalide. The key features include an anionic ortho-Fries rearrangement to furnish 3-iodosalicylamide, facile construction of the benzofuran system employing the
A practical strategy for the synthesis of both (–)- and (+)-concentricolide from salicylic acid has been developed. The key feature of the approach is sequential aromatic lithiation and condensation with an aldehyde directed by a chiral oxazoline unit derived either from L- or D-phenylalaninol, which is employed as an auxiliary.