# When the prefix cyclo- comes before the name of a hydrocarbon, what does it mean?

Feb 19, 2017

It means the beginning and the end of the alkane-chain are connected.

#### Explanation:

Cyclo-propane forms a triangle:

Cyclo-pentane does something similar:

I think you get the idea from here.

Note :
Because of the 'ends' connecting, the cyclo-alkanes are of the form ${C}_{n} {H}_{2 n}$ in stead of ${C}_{n} {H}_{2 n + 2}$, and thus isomeres of the mono-alkenes.