A process of manufacturing (6R,10R)-6,10,14-trimethylpentadecan-2-one in a multistep synthesis from 6,10-dimethylundeca-3,5,9-trien-2-one comprising the steps a) providing a mixture of (3E,5E)-/ (3E,5Z)-/ (3Z,5E)-/ and (3Z,5Z)-6,10-dimethylundeca-3,5,9-trien-2-one; b) separating at least one - and/or at least one -isomers of 6,10-dimethylundeca-3,5,9-trien-2-one from the mixture of step a); c) asymmetric hydrogenation of either 6,10-dimethylundeca-3,5,9-trien-2-one or a ketal of 6,10-dimethylundeca-3,5,9-trien-2-one using molecular hydrogen in the presence of a chiral iridium complex and yielding -6,10-dimethylundecan-2-one; d) chemically transforming -6,10-dimethylundecan-2-one to a mixture of (R,E)-6,10,14-trimethylpentadec-5-en-2-one and (R,Z)-6,10,14-trimethylpentadec-5-en-2-one; e) separating one isomer of 6,10,14-trimethylpentadec-5-en-2-one from the mixture obtained in step d); f) asymmetric hydrogenation of either 6,10,14-trimethylpentadec-5-en-2-one or a ketal of 6,10,14-trimethylpentadec-5-en-2-one using molecular hydrogen in the presence of a chiral iridium complex and yielding (6R,10R)-6,10,14-trimethylpentadecan-2-one; wherein the steps a)-f) are in the order a,b,c,d,e,f; with the proviso that if in the step c) the ketal is hydrogenated before the step c) a step c o) takes place c o) forming a ketal of the isomer of 6,10-dimethylundeca-3,5,9-trien-2-one separated in step b); and that in step c) the ketal of 6,10-dimethylundeca-3,5,9-trien-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding -6,10-dimethylundecan-2-one; or if in the step f) the ketal is hydrogenated before the step f) a step f o) takes place f o) forming a ketal of the isomer of 6,10,14-trimethylpentadec-5-en-2-one separated in step e); and that in step f) the ketal of 6,10,14-trimethylpentadec-5-en-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding (6R,10R)-6,10,14-trimethylpentadecan-2-one. a) providing a mixture of (3E,5E)-/ (3E,5Z)-/ (3Z,5E)-/ and (3Z,5Z)-6,10-dimethylundeca-3,5,9-trien-2-one; b) separating at least one - and/or at least one -isomers of 6,10-dimethylundeca-3,5,9-trien-2-one from the mixture of step a); c) asymmetric hydrogenation of either 6,10-dimethylundeca-3,5,9-trien-2-one or a ketal of 6,10-dimethylundeca-3,5,9-trien-2-one using molecular hydrogen in the presence of a chiral iridium complex and yielding -6,10-dimethylundecan-2-one; d) chemically transforming -6,10-dimethylundecan-2-one to a mixture of (R,E)-6,10,14-trimethylpentadec-5-en-2-one and (R,Z)-6,10,14-trimethylpentadec-5-en-2-one; e) separating one isomer of 6,10,14-trimethylpentadec-5-en-2-one from the mixture obtained in step d); f) asymmetric hydrogenation of either 6,10,14-trimethylpentadec-5-en-2-one or a ketal of 6,10,14-trimethylpentadec-5-en-2-one using molecular hydrogen in the presence of a chiral iridium complex and yielding (6R,10R)-6,10,14-trimethylpentadecan-2-one; with the proviso that if in the step c) the ketal is hydrogenated before the step c) a step c o) takes place c o) forming a ketal of the isomer of 6,10-dimethylundeca-3,5,9-trien-2-one separated in step b); and that in step c) the ketal of 6,10-dimethylundeca-3,5,9-trien-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding -6,10-dimethylundecan-2-one; if in the step c) the ketal is hydrogenated before the step c) a step c o) takes place c o) forming a ketal of the isomer of 6,10-dimethylundeca-3,5,9-trien-2-one separated in step b); and that in step c) the ketal of 6,10-dimethylundeca-3,5,9-trien-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding -6,10-dimethylundecan-2-one; c o) forming a ketal of the isomer of 6,10-dimethylundeca-3,5,9-trien-2-one separated in step b); and that in step c) the ketal of 6,10-dimethylundeca-3,5,9-trien-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding -6,10-dimethylundecan-2-one; or if in the step f) the ketal is hydrogenated before the step f) a step f o) takes place f o) forming a ketal of the isomer of 6,10,14-trimethylpentadec-5-en-2-one separated in step e); and that in step f) the ketal of 6,10,14-trimethylpentadec-5-en-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding (6R,10R)-6,10,14-trimethylpentadecan-2-one. if in the step f) the ketal is hydrogenated before the step f) a step f o) takes place f o) forming a ketal of the isomer of 6,10,14-trimethylpentadec-5-en-2-one separated in step e); and that in step f) the ketal of 6,10,14-trimethylpentadec-5-en-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding (6R,10R)-6,10,14-trimethylpentadecan-2-one. f o) forming a ketal of the isomer of 6,10,14-trimethylpentadec-5-en-2-one separated in step e); and that in step f) the ketal of 6,10,14-trimethylpentadec-5-en-2-one is asymmetrically hydrogenated and after the asymmetric hydrogenation the hydrogenated ketal is hydrolysed to the ketone and yielding (6R,10R)-6,10,14-trimethylpentadecan-2-one.