Abstract: Compounds of formula (I), wherein A is a hydrogen atom or a hydroxyl group; B is a hydrogen atom or a C.sub.1-8 alkyl, C.sub.1-8 alkenyl, C.sub.1-8 fluoroalkyl or C.sub.1-8 perfluoroalkyl group; each of R.sub.1, R.sub.2 and R.sub.5, which are the same or different, is a hydrogen atom, a halogen such as chlorine, bromine or fluorine, a C.sub.1-8 alkyl, C.sub.1-8 alkenyl, C.sub.3-8 cycloalkyl, C.sub.3-8 cycloalkenyl, C.sub.6, C.sub.10 or C.sub.14 aryl, C.sub.1-6 alkoxycarbonyl, C.sub.1-6 hydroxyalkyl, C.sub.1-6 alkoxyalkyl, C.sub.1-6 alkoxy, C.sub.1-8 fluoroalkyl or C.sub.1-8 perfluoroalkyl group, or R.sub.1 and R.sub.2 taken together form a C.sub.3-8 cycloalkyl, C.sub.3-8 cycloalkenyl or C.sub.6, C.sub.10 or C.sub.14 aryl ring, except for compounds in which R.sub.1 and R.sub.2 are both hydrogen; each of R.sub.3 and R.sub.4, which are the same or different, is a hydrogen atom or a C.sub.1-8 alkyl, C.sub.1-8 alkenyl, C.sub.3-8 cycloalkyl or C.sub.3-8 cycloalkenyl group, or R.sub.3 and R.sub.

Abstract: Compounds of general formula (I) ##STR1## in which: A represents either a hydrogen atom, a hydroxyl, a C.sub.1-6 hydroxyalkyl group, a thiol, a C.sub.1-6 alkylsulphanyl group, an amino group, a C.sub.1-6 alkylamino group, a di(C.sub.1-6 alkyl)amino group, a C.sub.1-6 alkylhydroxylamine group, a C.sub.1-6 alkoxy group, a hydroxylamine group, an N,O-di(C.sub.1-6 alkyl)hydroxylamine group, an azido or a halogen such as fluorine, chlorine or bromine, B represents a hydrogen atom, a linear or branched C.sub.1-6 alkyl group, a C.sub.2-6 alkenyl group, a C.sub.1-6 fluoroalkyl group, a C.sub.1-2 perfluoroalkyl group, a C.sub.1-6 alkoxy group, a phenyl group or an oxo group, X represents an oxygen or sulphur atom.Application in therapeutics.