1. 20.2 Synthetic route HL only Syed Arshad Mushtaq Chemistry Teacher
Australian School of Abu Dhabi

2. Learning outcomes Understand:
Synthesising organic compounds stems from readily available starting material via a series of separate steps. The basis of synthetic routes involves functional group interconversions.
Synthetic design often involves retro-synthesis of organic compound
Apply knowledge to:
Deduce multi-step synthetic routes given starting reagents and the product(s)

3. Clarification notes
Only conversions involving four or less discrete steps will be assessed in synthetic routes.
Any of the reaction types covered in Topic 10 and sub-topic 20.1 can be used.

4. When given the starting substance and the product, you should be able to predict a reaction route.
This may be a series of steps.
You will be expected to know up to four steps to reach a product.
You must also give conditions for each stage if known.

6. Possible conversions

7. Useful list of the reactions

8. Let’s try some conversion

9. Example
Convert Ethane to ethanoic acid in four steps

10. UNDERSTANDING/KEY IDEA 20.2.B
Retro-synthesis of organic compounds.

11. Retro-synthesis
Retro-synthesis simply means working backwards from the desired product to the starting material.
The desired product is the “target molecule”.
This “target molecule” is the starting point for our thinking.
It is systematically broken down into precursors which get us to the starting material.

12. Example 1
Explain how propyl propanoate can be synthesized from a single carboxylic acid. Give equations and conditions for all reactions, and state the type of reaction occurring at the functional group at each step.

13. Example 2
You are required to make butanone starting from any alkene of your choice. Show the steps involved in retro-synthesis to determine the identity of the alkene.