CuLi2Cl4 catalysed cross-coupling strategy for the formal synthesis of the diterpenoid (+)-subersic acid from (–)-sclareol. (1st July 2017)

• Record Type: Journal Article
• Authors: Wu, Qiangyong; Wang, Peiqiang; Zhou, Bin; Hua, Sikai; Ren, Jiangmeng; Zeng, Bu-Bing
• Is Part Of: Journal of chemical research. Volume 41:Number 7(2017)
• Page Start: 394
• Page End: 397
• Publication Date: 2017-07-01
• Subjects: Chemistry -- Research -- Periodicals; Chemistry -- Periodicals; 540.5
• DOI: 10.3184/174751917X14967701766923
• Languages: English
• ISSNs: 1747-5198

Abstract

A CuLi2Cl4-catalysed regioselective cross-coupling is used in a key step leading to the concise synthesis of (+)-subersic acid with an overall yield of 25.7% from commercially available (–)-sclareol. The coupled product 15-(2-methoxy-5-carbomethoxy)phenyl-labda-8(9), 13-E-diene was obtained in 62% yield under CuLi2Cl4 conditions starting from 2-iodo-4-carbomethoxyanisole and 15-acetoxy-labda-8(9), 13-E-diene. These were derived from 4-hydroxybenzoic acid and (–)-sclareol respectively. The 15-(2-methoxy-5-carbomethoxy)phenyl-labda-8(9), 13-E-diene was easily transformed into (+)-subersic acid by demethylation of the phenol ether and ester. This cross-coupling strategy showed a good functional group tolerance and various (+)-subersic acid derivatives were obtained in moderate yields.