Isomer mixtures of unsaturated macrocyclic musk compounds

A fragrance substance mixture comprising:

• (a) a first compound (E) and a second compound (Z), both having the same chemical formula, wherein the first compound (E) and the second compound (Z) are individually selected from the group consisting of oxacyclohexadecen-2-one and 17-oxacycloheptadec-9-en-1-one, and wherein the first compound (E) is trans-configurated and the second compound (Z) is cis-configurated, and
• wherein the first compound (E) and the second compound (Z) are in a weight ratio of 10:90 to 60:40 ((E):
• (Z));
• and
• (b) one or more additional fragrance substances that are not compound(s) of formula (I)
• wherein one of the four wavy lines denotes a double bond and the remaining wavy lines denote a single bond, respectively, and X is selected from —O—, —CH2— and —O—CH2—;
• wherein,
• the one or more additional fragrance substances of (b) are selected from ketones and esters having a molar mass in a range of 150 to 285 g/mol and exhibit a pleasant olfactory impression,
• the first compound (E) and the second compound (Z) are in a total amount in the fragrance substance mixture that enhances the pleasant olfactory impression of the one or more additional fragrance substances of (b), and
• the total amount of the first compound (E) and the second compound (Z) in the weight ratio of 10:90 to 60:40 enhances the pleasant olfactory impression of the one or more additional fragrance substances of (b) more than the same total amount of the first compound (E) and the second compound (Z) in a weight ratio outside of the weight ratio of 10:90 to 60:40.