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Organic Synthesis

Key Terminology
Term Definition
Organic Synthesis Artificial execution of organic reactions to obtain a useful target molecule
The synthesis of an organic compound can involve several steps. For the AQA specification, you are
expected to be able to create a synthesis with up to four steps, using reactions studied in the
specification.
Chemists aim to design production methods with fewer steps that have a high percentage atom
economy, in order to minimise waste, keep costs effective and ensure as pure a product as possible is
produced. They also aim to have processes that do not require a solvent, as its removal may be difficult
and expensive. Starting materials should be non-hazardous to ensure safety of chemists.
A scheme can be deduced by drawing out the starting molecule and the target molecule. Then consider
the product of possible reactions of the starting molecules and reactions which produce the target
molecule. Then find a way of linking these routes, perhaps with another step.
The reactions of all of the following functional groups may be involved, and all conditions may be
required so it is worthwhile revisiting all AS and A2 mechanisms:
• Alkanes
• Alkenes
• Halogenoalkanes
• Alcohols
• Amines
• Amides
• Arenes
• Nitriles
• Aldehydes
• Ketones
• Acid Derivatives
• Arenes
These are some important notes to consider:
• When lengthening a carbon chain, a cyanide ion will need to react with a halogenoalkane
• Reducing Agents have different strengths
– NaBH4 for Carbonyls as it reduced polar bond only
– Hydrogen with Nickel Catalyst for Alkenes and Nitriles
– Tin and HCl for reducing compounds to amines
• Potassium Dichromate is an Oxidising Agent for Alcohols to Carbonyls

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