Compounds of formula (I) are suitable for use as herbicides: wherein R is methyl, ethyl, vinyl, ethynyl or cyclopropyl, R1 is hydrogen, C1-C6alkyl, C1-C6haloalkyl, C3-C7cycloalkyl, C1-C6alkoxy, C1-C6haloalkoxy, vinyl, propenyl, ethynyl, propynyl, halogen, or optionally substituted phenyl, R2 is methyl, ethyl, vinyl, ethynyl or methoxy, R3 and R4 are hydrogen or together form a double bond, A is C3-C7cycloalkyl which is unsubstituted or substituted once or twice by C1-C6alkyl, C1-C6haloalkyl, C1-C6alkoxy, C1-C6alkylcarbonyloxy, C2-C6alkenyl, ═O or ═N—R10, or A is cyclohexyl substituted once, at the 4-position, by one (C3-C6cycloalkyl)methoxy, C3-C6cycloalkyloxy, C2-C5alkenyl-CH2-oxy, or benzyloxy substituent, or A is decahydro-1-naphthyl or decahydro-2-naphthyl, or A is optionally substituted phenyl, and G is hydrogen or an agriculturally acceptable metal, sulfonium, ammonium or a latentiating group.