To obtain the subject new compound useful as a controller for just, having inhibitory actions on germination of spore of fungus as a cause for rust.
This compound is shown by formula I [R1 and R2 are each H or OH; R3 is H or a halogen; R4 is a group of formula II (R5 and R6 are each H or a 1-6C alkyl; R7 is H or a 1-3C alkyl), etc.], such as 5,8- dihydroxy-2-[1-hydroxy-4-methyl-1-(3-methylbutyl)pentyl]-1,4-naphthoquinone. The compound of formula I is obtained reacting a (substituted) naphthalene of formula III (R44 to R46 are each H, methyl or benzyl: R47 is methyl, benzyl, etc.), with a base such as a lithium compound to give a metal salt, reacting the metal salt with a carbonyl compound of formula IV to give a naphthalene of formula V, carrying out oxidation reaction, eliminating the hydroxyl protecting group to give a compound of formula VI. The reaction temperature is preferably -78 to 50°C. After the reaction is finished, the naphthalene of formula V is isolated.
Takeda, Masakazu
Tanaka, Masahiko
