Answer:
18:3 Δ 9,12,15
Explanation:
Unsaturated fatty acids systematic numbering takes into account the number of unsaturations where do they start and the number of carbon atoms staring C1 as the carbon in the carboxylic group.
The general form of this numbering is:
N:U Δn1, n2 ...
Where N is number of carbon atoms, U is the number of unsaturations and n1, n2, is the number of the carbon where the double bonds starts. For example Oleic Acid have 18 Carbon Atoms, 1 Unsaturation and that unsaturation starts at the carbon 9, then the systematic numbering is 18:1 Δ 9.
If you apply this systematic numbering to the Linolenic acid the result should be: 18:3 Δ 9,12,15
