Patent ID: 7476756

Claim:
A compound of the formula (I): in which R 1 represents a C 5-26 -alkyl, C 5-26 -alkenyl or C 5-26 -alkynyl group or a polyunsaturated aliphatic carbon group comprising between 5 and 26 carbon atoms and comprising at least two unsaturations chosen from double and triple bonds; R 2 represents a hydrogen atom or a C 1-6 -alkyl group; R 3 represents a hydrogen atom or a C 1-3 -alkyl group; and R 4 represents a hydrogen atom or a C 1-4 -alkyl, C 3-7 -cycloalkyl or C 3-7 -cycloalkyl-C 1-3 -alkyl group; or a hydrate or a solvate thereof.