Question

Ethyl 2-methyl-5-oxocyclopentane-1-carboxylate

The rules say that functional groups are given more priority than side chains but if there is more than one functional groups then we consult the priority table for nomenclature...

Hence the ester group is given more priority over the ketone group. But then while naming the cyclopentyl group, shouldn't we give the ketone group the smaller number than the methyl group? Why didn't we call it ...5-methyl-2-oxocyclopentane...?

Answer 1

The ester group is given higher priority over the ketone group because esters have a higher priority according to the priority table for nomenclature. The correct name is ethyl 2-methyl-5-oxocyclopentane-1-carboxylate and not 5-methyl-2-oxocyclopentane.

Step-by-step explanation:

When naming the compound ethyl 2-methyl-5-oxocyclopentane-1-carboxylate, we need to prioritize the functional groups.

The ester group is given higher priority over the ketone group because esters have a higher priority according to the priority table for nomenclature.

The cyclopentyl group is named next, and the position of the ketone group is determined based on the lowest possible number. Therefore, the correct name is ethyl 2-methyl-5-oxocyclopentane-1-carboxylate and not 5-methyl-2-oxocyclopentane.