Abstract: Disclosed is a laevorotatory enantiomer of the configurational stereoisomer of difethialone, named homo-stereoisomer, the formula of which is 3-(4?-bromobiphenyl-4-yl)-1-(4-hydroxythiocoumarin-3-yl)-1,2,3,4-tetrahydronaphthalene, in which carbons 1 and 3 of the 1,2,3,4-tetrahydronaphthalene group have the same absolute configuration.

Abstract: Disclosed is a dextrorotatory enantiomer of the configurational stereoisomer of difethialone, named homo-stereoisomer, the formula of which is 3-(4?-bromobiphenyl-4-yl)-1-(4-hydroxythiocoumarin-3-yl)-1,2,3,4-tetrahydronaphthalene, in which carbons 1 and 3 of the 1,2,3,4-tetrahydronaphthalene group of the homo-stereoisomer have the same absolute configuration.

Abstract: Disclosed is a configurational stereoisomer, named enantiomer E1, of bromadiolone having, by chromatographic analysis of bromadiolone including four configurational stereoisomers of bromadiolone performed under the conditions described below, a retention time t1 having a value such that t1<t2<t3<t4; t2, t3 and t4 being the retention times of the configurational stereoisomers of bromadiolone different from the enantiomer E1, the analysis being performed at a temperature of 27.3° C.

Abstract: Disclosed is a composition including flocoumafen and an amount of a configurational stereoisomer of flocoumafen, named enantiomer E4, such that the ratio of this amount to the amount of flocoumafen in the composition is less than 10%, the enantiomer E4 being present with the exclusion of a racemic mixture, the enantiomer E4 having, by chromatographic analysis of flocoumafen, a retention time t4 having a value such that t1<t2<t3<t4; t1, t2 and t3 representing the retention times of the configurational stereoisomers of flocoumafen different from the enantiomer E4, the chromatographic analysis being performed at a temperature of 23.5° C.

Abstract: Disclosed is to a laevorotatory enantiomer of the configurational stereoisomer of difethialone, named hetero-stereoisomer, the formula of which is 3-(4?-bromobiphenyl-4-yl)-1-(4-hydroxythiocoumarin-3-yl)-1,2,3,4-tetrahydronaphthalene, in which carbons 1 and 3 of the 1,2,3,4-tetrahydronaphthalene group have different absolute configurations.