The use of trifluoroacetaldehyde ethyl hemiacetal or hydrate in a simple and practical regioselective synthesis of beta-hydroxy-beta-trifluoromethyl ketones from enamines and imines.
The reaction of trifluoroacetaldehyde ethyl hemiacetal or hydrate with an equimolar amount of enamines, derived from various methyl ketones, smoothly proceeded to give the corresponding beta-hydroxy-beta-trifluoromethyl ketones in high yields. An equimolar amount of imines derived from various methyl ketones with aliphatic, aromatic, and heteroaromatic substituents also readily reacted with trifluoroacetaldehyde ethyl hemiacetal or hydrate to afford the corresponding beta-hydroxy-beta-trifluoromethyl ketones in good to excellent yields. Difluoroacetaldehyde ethyl hemiacetal as well as pentafluoropropionaldehyde also participated in the reaction, affording good yields of the corresponding beta-hydroxy-beta-difluoromethyl or beta-pentafluoropropyl ketones.
Funabiki
Kazumasa
K
Department of Materials Science and Technology, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan. kfunabik@apchem.gifu-u.ac.jp
Matsunaga
Kei
K
Nojiri
Miwa
M
Hashimoto
Wataru
W
Yamamoto
Hitoshi
H
Shibata
Katsuyoshi
K
Matsui
Masaki
M