PURPOSE: To obtain a new derivative synthesizable in an industrially advantageous way, and useful as a highly safe herbicide having assured effect at lower doses good in selectivity for crops.
CONSTITUTION: This derivative (salt) is expressed by formula I or formula II [R1 is a (substituted) 1-6C alkyl or a (substituted) phenyl, etc.; R2 is a halogen, (substituted) 1-6C alkoxyl, etc.; (n) is 0-4; R3 and R4 are each H or a (substituted) 1-6C alkyl; R5 is a halogen, OCN, etc.), e.g. 2-acetoxy-5-ethoxycarbonyl-3-(3- methoxy-2-methyl-4-methylsulfonylbenzoyl)-5-methyl-2-bicyclo[4.1.0]hepten-4-one. This derivative can be obtained by reaction of a trione form of formula III with a compound of formula R6COX [R6 is a (substituted) 1-6C alkyl, a (substituted) alkenyl, etc.] in a solvent at -20°C to room temperature in the presence of a base for 0.5 to several tens hours.
SUGIURA TADASHI
YANAKA SATORU
ADACHI HIROYUKI
TOMITA KAZUYUKI
TAKAHASHI AKIHIRO
KAWANA TAKASHI