Regioselective synthesis of 6-alkyl- and 6-prenylpolyhydroxyisoflavones and 6-alkylcoumaronochromone derivatives.
The palladium-catalyzed coupling reaction of 6-iodoisoflavone, prepared from 3'-iodoacetophenone derivative, with 2-methyl-3-butyn-2-ol gave 6-alkynylisoflavone derivative, which was hydrogenated to give 6-alkylhydroxyisoflavone (luteone hydrate) (2). Dehydration of 2 gave 2',4',5,7-tetrahydroxy-6-prenylisoflavone (luteone) (1). Wighteone hydrate (3) was also synthesized from 6-iodotris(benzyloxy)isoflavone in a similar manner. 6-Alkyl-4'5,7-trihydroxy-coumaronochromone (4) was synthesized by oxidative cyclization of 2 with o-chloranil.
Tsukayama
Masao
M
Department of Chemical Science and Technology, Faculty of Engineering, The University of Tokushima, Minamijosanjima-cho, Tokushima 770-8506, Japan. tukayama@chem.tokushima-u.ac.jp
Wada
Hironari
H
Kawamura
Yasuhiko
Y
Yamashita
Kazuyo
K
Nishiuchi
Masaki
M
D001572:Benzofurans / Q000138:chemical synthesis*; D007529:Isoflavones / Q000138:chemical synthesis*; D013237:Stereoisomerism
D001572:Benzofurans; D007529:Isoflavones