Patent ID: 7452921

Claim:
A compound of formula (I): where: R 1 represents a methyl group, an ethyl group, a C 5 or C 6 cycloalkyl group or a C 6 -C 10 aryl group, said aryl group being unsubstituted or being substituted by at least one C 1 -C 4 alkyl or C 1 -C 4 alkoxy group; Z represents a C 6 -C 10 arylene group or a group of formula —(CHR 4 ) n —, where R 4 represents a hydrogen atom, a hydroxy group or a C 1 -C 4 alkyl group, and n is a number from 0 to 6; Y represents a carbonyl group or a —CH 2 — group, provided that R 4 represents a hydroxy group when Y represents a —CH 2 — group; Q represents a residue of a mono- or poly-hydroxy compound having from 1 to 6 hydroxy groups; and x is a number from 1 to 6; and esters thereof.