Chemistry Letters, Vol.36, No.1, 8-9, 2007
Effective synthesis of 5-substituted butenolide derivatives by using cinchonidine-derived quaternary ammonium phenoxide catalyst
A vinylogous aldol-type reaction between 4-methyl-2-(trimethylsiloxy)furan and aldehydes catalyzed by cinchonidinederived quaternary ammonium phenoxide proceeded smoothly to afford the corresponding 5-substituted butenolide derivatives in high yields with good to excellent diastereo- and enantio-selectivities.