Just as you can oxidise alcohols to form compounds with a carbonyl group, you can then reduce carbonyl containing compounds back to alcohols.
Reagents for reduction
- Lithium aluminium hydride LiAlH4
- Sodium borohydride NaBH4
Structures of the reducing agents
Read through your text and annotate your notes find the answers to the questions below.
✍️ What difference is there in the conditions under which the two reagents might be used?
✍️ Which reagent is preferred from the reduction of carboxylic acids and why?
Reduction of Carbonyl Containing Compounds
✍️ For the following starting materials, draw the structures and name to products formed when treated with lithium aluminium hydride.
- propanoic acid
Conversion of nitrobenzene to phenylamine
This reduction happens via a two step process as summarised below.
✍️ After reading your text or other sources, elaborate on what is happening in both stages in your notes. Make sure you can answer these questions.
- Why is a protonated phenylammonium ion produced in the first step?
- What technique is used to heat the reaction?
- What is the role of the tin?
- What is the purpose of using sodium hydroxide in the second stage?