Question

Hi. I was wondering if you could help me with some chemical nomenclature.

In the case of a hydrocarbon with a double bond, for instance, CH2=CHCH2CH2CH=CHCH2CH2CH3, my professor teaches that it is called nona-1,5-diene - however my textbook says it is called 1,5-nonadiene.

Would you maybe know why my professor writes the name in a different way - is his way better or ... ?

Answer 1

Both the names i.e. nona-1,5-diene and 1,5-nonadiene for the hydrocarbon given are correct. But your professors's way for naming the organic compound is much more appreciable because he is following the IUPAC guidelines for nomenclature of an organic compound.

As per the rule, if the parent chain has any substituents, then they were come first at the time of numbering which is called prefix, then parent chain and then suffix. Here we should also follow the same rule,i.e. the nona for the nine carbon atoms will come first, then the suffix i.e. 1,5-diene.

So, I think your professors way for the nomenclature of the organic hydrocarbons is more appropriate and easy for the student to understand as compared to your text book.