A convenient synthesis of α-trifluoremethylated and α-perfluoroalkylated acyloins from α-hydroxy acids
作者:Masami Kawase、Teruo Kurihara
DOI:10.1016/0040-4039(94)88284-3
日期:1994.10
A novel transformation of α-hydroxy acids to α-trifluoremethylated and α-perfluoroalkylated acyloins was efficiently realized by utilizing trifluoroacetic or perfluoroalkylcarboxylic anhydrides in the presence of pyridine, in which probable intermediates were meso-ionic 1,3-dioxolium-4-olates.
Process for producing 4,4,4-trifluoro-3-hydroxybutyric acid derivatives
申请人:——
公开号:US20020016511A1
公开(公告)日:2002-02-07
A first process for producing an optically active perfluoroalkylcarbinol derivative includes (a) reacting an optically active imine with a compound that is a hemiacetal of a perfluoroalkylaldehyde or a hydrate of a perfluoroalkylaldehyde to obtain a condensate; and (b) hydrolyzing the condensate under an acid condition. A second process for increasing optical purity of an optically active 4,4,4-trifluoro-3-hydroxy-1-aryl-1-butanone derivative includes (a) precipitating a racemic crystal of the derivative, from the derivative; and (b) removing the racemic crystal from the derivative. A third process for increasing optical purity of the butanone derivative includes recrystallizing the derivative. Novel compounds are optically active and inactive 4,4,4-trifluoro-3-hydroxybutanoic aryl ester derivatives. A fourth process for producing an optically active or optically inactive 4,4,4-trifluoro-3-hydroxybutyric acid aryl ester derivative includes oxidizing an optically active or optically inactive 4,4,4-trifluoro-3-hydroxy-1-aryl-1-butanone derivative. A fifth process for increasing optical purity of the optically active aryl ester derivative includes recrystallizing the derivative. A sixth process for producing an optically active 4,4,4-trifluoro-1,3-butanediol includes reducing the optically active aryl ester derivative by a hydride. A seventh process for producing an optically active or inactive 4,4,4-trifluoro-3-hydroxybutyric acid alkyl ester derivative includes reacting under an acid condition the optically active or optically inactive aryl ester derivative with a lower alcohol. It is possible to suitably combine at least two of the first to seventh processes.