Naming Organic Compounds

  How do you know it’s organic? The formula will start with a C followed by H’s. Most of the organic carbons you will encounter will be either hydrocarbons or alcohols, and luckily for you, these are the

  simplest of all to name. Learn the list of prefixes in the table following this section: they correspond to the number of carbons present in the compound. The following silly statement will help you remember the order of the first four prefixes since they are not ones you are familiar with: “Me eat peanut butter.” This corresponds to meth-, eth-, prop-, and but-, which correspond to one, two, three, and four carbons, respectively.

  Now that we have a stem, we need an ending. There are three common hydrocarbon endings; the ending changes depending on the structure of the molecule:

  ●-ane = alkane (all single bonds and saturated); CnH2n

  +2; saturated: it contains the maximum

  number of H’s

  ● -ene = alkene (contains double bond, unsaturated); Cn




  -yne = alkyne (contains triple bond, unsaturated); CnH2n

  -2; polyunsaturated: it contains more

  than one double or triple bond

  For any hydrocarbon, you can remove one H and replace it with a hydroxyl group, or —OH group, to

  form an alcohol. Do not be fooled—this looks like a hydroxide group but isn’t! The OH does not make this hydrocarbon an alkaline or basic compound, nor do you name it as a hydroxide! C2H6 is ethane, while C2H5OH is ethanol. Fill in the missing formulas and names for each compound in the table: