Alcohols

 

Simple alcohols (ROH) have as their common names the name of the alkyl group followed by the word alcohol. The functional group "OH" is referred to as "hydroxy".

Methane: CH4

Methyl alcohol: CH3OH

Methanol is the preferred name of this poisonous material in order to dissociate it in labeling from the less toxic ethyl alcohol.

 

  1. Give the common names for the compounds:

    2.  

     

    (a) Isopropyl alcohol

    (b) tert-Butyl alcohol

     

     

     

     

    In the IUPAC names for alcohols, the final "e" of the hydrocarbon name is replaced by "ol" and the position of the hydroxy group is indicated by the lowest possible number; the longest chain containing the hydroxy group (which may not be the longest chain in the molecule) is used to determine the parent name.

     

     

  2. Give IUPAC names for the following alcohols:

 

 

 

 

 

 

 

 

 

3. Give the common names of all possible alcohols of the formula C4H10O.

 

 

 

 

 

 

  1. Which of the above compounds are primary alcohols?

    2. Secondary?

    Tertiary?

     

     

     

    Primary: n-Butyl alcohol and isobutyl alcohol

    Secondary: sec-Butyl alcohol

    Tertiary: tert-Butyl alcohol

     

     

     

     

  2. What is the IUPAC name of tert-butyl alcohol?

    3.  

     

    2-methyl-2-propanol

    (Note that tert-butanol is an incorrect

    name as it is derived by mixing common

    and IUPAC names.)

     

     

     

     

     

    Many compounds contain more than one hydroxy group. Simple compounds containing two hydroxy groups are commonly referred to as glycols or systematically, "diols". Compounds with three hydroxy groups are "triols". The principal ingredient in automobile antifreeze is "ethylene glycol":

    HOCH2CH2OH

    The systematic names for this substance is 1,2-ethanediol. (Note: When a suffix is attached to a hydrocarbon name, the final "e" is not dropped if the suffix begins with a consonant.)

  3. Glycerin and glycerol, the common names for a substance obtained by hydrolysis of animal and vegetable fat, has the following structure.

    4. What is the systematic name for this compound?

     

     

    1,2,3-propanetriol

     

     

     

  4. Give the IUPAC name for the following compound:

 

 

 

 

1,2-cyclohexanediol

 

 

 

 

With certain complex structures, it is necessary, or at least convenient, to use the prefix hydroxy for —OH groups, e.g.,

 

CH3CH2CH2COOH

Butanoic acid

HOCH2CH2CH2COOH

4-Hydroxybutanoic acid

 

 

 

8. Name the following compound:

 

 

2,3-Dihydroxybutanoic acid

 

 

 

9. Name the following compounds:

 

 

 

 

 

 

10. Name the following compound:

 

1,6-dichloro-2,5-dimethyl-2,5-hexanediol

(greater number of substituents, hence preferred over
2,5-bis(chloromethyl)-2,5-hexanediol)

 

 

 

 

 

Metal Salts of Alcohols:

Metal salts of simple alcohols are usually named by using the suffix "—oxide" as illustrated in the following examples:

CH3OH Methyl alcohol

CH3ONa Sodium methoxide

t-BuOH tert-Butyl alcohol

t-BuOK Potassium tert-butoxide

Systematic names are formed by changing the parent suffix "ol" to "olate":

(CH3CH2)3COH 3-Ethyl-3-pentanol

(CH3CH2)3COK Potassium 3-ethyl-3-pentanolate

 

11. Give two names for the following compound:

 

(CH3)2CHCH2ONa

 

 

 

(CH3)2CHCH2ONa

Sodium isobutoxide

Sodium 2-methyl-1-propanolate

 

 

 

 

 Go to the Chapter on

Amines