Compound of formula (i) wherein R is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R' is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R 1 is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R 2 is selected from the group consisting of wherein R 3 is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, or (ii) wherein R', R 2 and R 3 are independently selected from the groups as defined in (i), respectively, and R and R 1 are bonded together to form a saturated or unsaturated ring system comprising 5 to 10 carbon atoms, preferably wherein the ring system additionally carries one, two or more C 1 to C 5 linear, branched or cyclic alkyl, alkenyl or alkadienyl substituents, or (iii) wherein R', R 1 and R 2 are independently selected from the groups as defined in (i), respectively, and R and R 3 are bonded together to form a saturated or unsaturated, mono or bicyclic, ring system comprising 5 to 10 carbon atoms and optionally 1 or 2 ether functional groups, preferably wherein the ring system additionally carries one, two or more C 1 to C 5 linear, branched or cyclic alkyl, alkenyl or alkadienyl substituents. (i) wherein R is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R' is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R 1 is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R 2 is selected from the group consisting of wherein R 3 is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, or wherein R' is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R 1 is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, and wherein R 2 is selected from the group consisting of wherein R 3 is selected from the group consisting of hydrogen and C 1 to C 10 linear or cyclic alkyl, alkenyl or alkadienyl residues, preferably wherein the residues additionally carry one, two or more C 1 to C 4 linear, cyclic or branched alkyl, alkenyl or alkadienyl substituents, (ii) wherein R', R 2 and R 3 are independently selected from the groups as defined in (i), respectively, and R and R 1 are bonded together to form a saturated or unsaturated ring system comprising 5 to 10 carbon atoms, preferably wherein the ring system additionally carries one, two or more C 1 to C 5 linear, branched or cyclic alkyl, alkenyl or alkadienyl substituents, or (iii) wherein R', R 1 and R 2 are independently selected from the groups as defined in (i), respectively, and R and R 3 are bonded together to form a saturated or unsaturated, mono or bicyclic, ring system comprising 5 to 10 carbon atoms and optionally 1 or 2 ether functional groups, preferably wherein the ring system additionally carries one, two or more C 1 to C 5 linear, branched or cyclic alkyl, alkenyl or alkadienyl substituents.