Alicyclics and Aromatics

Rings of carbon are formed when a group of hydrocarbon come together to form a enclosed shape for example a hexagon. Their general formulais CnH2n, and when naming them, just add the prefix "CYCLO" infront of the main branch's name. for example, if a propane carbon chain has formed a triangle, it would be named as cyclopropane.

Cyclopropane

The cyclic hydrocarbons are more reactive, less stable and can also be branched. Cyclic hydrocarbons need at least three carbon atoms for it to form a ring.
When naming the compound, you can start from carbon atom and go clockwise or counter-clockwise. If there is only one side group, you do not need to put a number because we assume it starts at the very first carbon. When there is more than one side group, count clockwise or counter-clockwise from the first side group so that the lowest numbers are used.

cyclohexanone

Cyclic substituents are named the same way as they are in simple chains.
If there is a tie, we always sort them by alphabetical order.
Alkenes and Alkynes do not need numbers unless there is more than one double/triple bond because we always assume the bond starts from the first carbon.

Aromatics:
They usually have pleasant odours and contains at least one benzene ring (C6H6) which is a cyclohydrocarbon with 3 double bonds between carbon atoms.
The double bonds are delocalized so they can go anywhere and they are less reactive than cycloalkenes and cycloalpynes because of this.

Benzene

When naming aromatics, we name all the side groups first and then end with benzene.
If the benzene is a side group, we call it phenyl.

This video will sum up what we learned and is a great study guide for the test~! Enjoy