Highly Enantioselective Conjugate Addition-Cyclization Cascade Reaction of Malonates with o-Hydroxycinnamaldehydes: Asymmetric Synthesis of 4-Substituted Chromanols
作者:Yongcheon Lee、Seung Woo Seo、Sung-Gon Kim
DOI:10.1002/adsc.201100324
日期:2011.10
The asymmetricorganocatalytic conjugate addition–cyclization reaction of malonates with o-hydroxycinnamaldehydes, which affords 4-substituted chroman-2-ols, has been established using a diphenylprolinol trimethylsilyl (TMS) ether as organocatalyst. The desired products were obtained with good to excellent yields and high enantioselectivities (up to >99% ee). Synthetically useful chroman derivatives