Chiral dihydropyranones via hetero Diels–Alder reaction of Danishefsky's diene and α-ketoesters: a high-throughput screening approach
作者:Christian Wolf、Zaid Fadul、Pili A. Hawes、Emily C. Volpe
DOI:10.1016/j.tetasy.2004.05.024
日期:2004.7
The chiral Lewis acid-catalyzed hetero Diels-Alder reaction between Danishefsky's diene and sterically hindered alpha-ketoesters has been optimized using a validated high-throughput screening method. The yields and enantioselectivities of three chiral dihydropyranones obtained by this multi-substrate one-pot screening approach are in excellent agreement with individual screening results. Employing ethyl benzoylformate, ethyl 3-methyl-2-oxobutyrate, and dihydro-4,4-dimethyl-2,3-furandione in one reaction mixture allowed a fast evaluation of chiral Lewis acid composition, solvent, temperature, catalyst loading, and dienophile concentration. The crude product mixtures were analyzed by HPLC using two chiral stationary phases coupled in series to avoid time-consuming work-up procedures. (C) 2004 Elsevier Ltd. All rights reserved.