Beta-hydroxyketone and its production

Compounds of the present invention are represented by the formula, wherein X represents a lower alkyl, lower alkoxy, lower haloalkyl or lower haloalkoxy group or a halogen atom, and R and R , which may be the same or different, represent a hydrogen atom or a methyl group. They are useful intermediates for preparing herbicidal compounds of the formula which compounds are obtained by dehydrating the corresponding compounds (I) with any of a certain number of acids. The compounds (I) are prepared by reaction of an aldehyde with an acetoacetic acid salt in the presence of a C1-6 carboxylic acid salt.