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Nomenclature of organic compounds. Explain, please?

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Root usually means the class of compound. So all alkanes will end in -ane. Propane, ethane, methane, etc.

All alkenes (double bond) will end in -ene. Propene, ethene, etc.

All triple bonded compounds (alkynes) will end in -yne, such as propyne.

It seems a bit confusing to put root in indicating the chain length. But it comes down to memorizing the word with the number of carbons. Eth- means 2 carbons, Prop- means three carbons.

So putting together two “roots” and propane means an alkane of three carbon atoms.

Now about prefix. That is something you put in front of the name. So take a three carbon alkane, and add a chlorine atom. It can be called chloropropane if the chlorine is on the end carbon. But what if it is on the middle carbon? Then, you would name it 2-Chloropropane, with the 2 being the location on the chain.

What may be confusing is the suffix, as it seems unclear from what I read.

That comes down to what I would term roots, like -ol meaning an alcohol. It is systematic, so the presence of a ketone means the name ends in -one.

So take a four carbon compound, put a chlorine on one carbon, and an -OH (alcohol) on another. If the alcohol is on the end carbon, and the chlorine on the opposite end, then the name would be 4-Chlorobutanol. (I would never use the name ethan-1-ol in your example, as it is redundant, since there is no other place the alcohol could be.)

Your example might want to name it 4-Chlorobutan-1-ol, but that becomes awkward, and 4-Chlorobutanol implies where the alcohol OH is located.

But take the four carbon chlorinated alcohol. And put the -OH on the second carbon atom. Then, if the chlorine is on the far end carbon, the name would be 4-Chlorobutan-2-ol.

Organic Compounds 002