The isoflavanoids 7-hydroxyisoflavanone 4a, 7-hydroxy-3', 4'-dimethoxyisofl
avanone 4b, 5, 7-dihydroxy-3', 4'-dimethoxylsoflavanone 4c, 5, 7-dihydroxy-
2'-methoxyisoflavanone 4d, 5, 7-dihydroxy-3', 4'-dimethoxyisoflavanone 4e a
nd 5, 7-dihydroxy-4'-methoxyisoflavanone 4f have been conveniently prepared
by using paraforomaldehyde and diethylamine as a base.