Patent ID: 8247479

Claim:
A compound of the formula Wherein R represents C 1 -C 20 alkyl, hydroxy-C 2 -C 8 alkyl, C 1 -C 20 alkanoyl, C 7 -C 13 aroyl, C 2 -C 20 alkenyl, C 1 -C 20 alkyl or C 2 -C 20 alkenyl interrupted by at least one heteroatom selected from the group consisting of O, S and N, C 6 -C 20 aryl, C 1 -C 12 alkyl-C 6 -C 20 aryl, C 6 -C 20 aryl, C 6 -C 20 aryl-C 1 -C 4 alkyl, mono- or bicyclic C 5 -C 20 cycloalkyl, mono- or bicyclic C 1 -C 12 alkyl-C 5 -C 20 cycloalkyl, or mono- or bicyclic C 5 -C 20 cycloalkyl-C 1 -C 4 alkyl; R 1 , R 2 , R 3 and R 4 independently of one another represent hydrogen or C 1 -C 3 alkyl; R 5 represents hydrogen or methyl; and R′, R 1 ′, R 2 ′, R 3 ′, R 4 ′ and R 5 ′ are as defined as R, R 1 , R 2 , R 3 , R 4 and R 5 .