A Diastereoselective, Nucleophile-Promoted Aldol-Lactonization of Ketoacids Leading to Bicyclic-beta-Lactones

作者:Liu Gang; Shirley Morgan E; Romo Daniel*
来源:Journal of Organic Chemistry, 2012, 77(5): 2496-2500.
DOI:10.1021/jo202252y

摘要

An improved, tandem acid activation/aldol-lactonization process is described. This more practical protocol shortens reaction times for the construction of bicyclic beta-lactones from ketoacids and implements the use of commercially available reagents p-toluenesulfonyl chloride (p-TsC1) as activator and 4-dimethylaminopyridine (4-DMAP) as nucleophllic promoter (Lewis base). Substrates with beta-substituents, with respect to the carboxylic acid, consistently showed excellent levels of diastereoselectivity during the bis-cyclization event.

  • 出版日期2012-3-2