Synthesis- Alcohols

Question 1

What are alcohols?

Answer 1

Substituted alkanes in which one or more of the
hydrogen atoms is replaced with a hydroxyl functional group, –OH
group

Question 2

How can alcohols be prepared?

Answer 2

• haloalkanes by substitution
• alkenes by acid-catalysed hydration (addition)
• aldehydes and ketones by reduction using a reducing agent such
  as lithium aluminium hydride

Question 3

Describe a dehydration reaction involving an alcohol.

Answer 3

Forms alkenes using aluminium oxide, concentrated
sulfuric acid or concentrated phosphoric acid

Question 4

Describe oxidation reactions of alcohols.

Answer 4

• oxidation of primary alcohols to form aldehydes and then carboxylic acids
• oxidation of secondary alcohols to form ketones

BOTH using acidified permanganate, acidified dichromate or hot copper(II)
oxide

Question 5

Describe the formation of alcoholic alkoxides.

Answer 5

Reacting with some reactive metals such as potassium or sodium, which can then be reacted with monohaloalkanes to form ethers

Question 6

Describe the formation of esters.

Answer 6

• Reacting with carboxylic acids using concentrated sulfuric acid or concentrated phosphoric acid as a catalyst
• Reacting with acid chlorides this gives a faster reaction than reaction with carboxylic acids and no catalyst is needed