The present invention relates to compounds of the following formula (I):or a pharmaceutically acceptable salt thereof, a stereoisomer or a mixture of stereoisomers in any proportion, in particular a mixture of enantiomers, and particularly a racemate mixture,in which R represents a (C1-C10)alkyl group substituted with one or more, preferably one or two, groups chosen from COOH and NHR1,with R1 representing a hydrogen atom or a -Alk, -C(O)-Alk or -C(O)O-Alk group, Alk representing a (C1-C6)alkyl group,as well as a method for preparing them, and their use as a medicine, notably for treating an infection with a retrovirus such as HIV.
