Esters of pentahydroxyhexylcarbamoyl alkanoic acids

A compound of formula V

• where R1 is an alkyl radical which has from 1 to 18 carbon atoms and in which at least one —CH2— group of the alkyl radical is optionally replaced by at least one group chosen from —O—, —CO—, —CH═CH—, —C≡C—, and aryl groups and the alkyl radical is optionally substituted by at least one halogen chosen from F, Cl, Br, and I.