Question

Is the name 2-ethyl-1-iodocyclopentane correct for the following compound?

Answer 1

1. Here the number of carbon atoms in the alkyl group (ethyl) is less than the number of carbon atoms in the cycloalkane ring (cyclopentane) attached with it. So cycloalkane chain will be considered as parent chain and the name will end up as cyclopetane.

2. The names of substituents attached with this parent chain are to be added as prefix with this parent chain in alphabetical order. Hence 'ethyl' will come first with locant-1 and then 'iodo' with locant -2 and the name of parent cycloalkaane i.e cyclopetane is finally added without any gap to complete the name of the compound as

`color(magenta)"1-ethyl-2-iodocyclopentane"`

Following examples may make the matter more clear . The numbering will be started from C- atom linked with `Br`, proceeding along the ring towards the C-atom linked with the next element `Cl` alphabetically .