Zusammenfassung der Ressource
ORGANIC SYNTHESIS OF ALIPHATIC COMPOUNDS
- ORGANIC SYNTHESIS
- A specialised branch of chemistry concerned with
producing organic compounds by chemical reactions
- May be simple or require more complex,
multi-step reactions involving many stages
- In industry, a multi-step synthesis of a complex organic molecule starts from a commercially availablle raw materia
- Crude oil is the raw material for many organic compounds
- Compounds derived from crude oil are also used as starting materials
- Often presented as a puzzle
- You may be supplied with reactions you've never seen before
- Using familiar + unfamiliar reactions you could be asked to suggest a
mult-istep synthesis of an organic compound from a supplied starting
material
- Stepwise approach to organic synthesis
- 1.Need a good knowledge of the chemical reactions, reagents and conditions in the specification
- 2. Should check carbon skeleton of starting material + product
- longer chain usually means that 2 C-containing compounds must be reacted
together
- 3. Examine the starting material and product to see if you can spot what has changed
- 4.Think about working backwards
- 5. Finally check you answer and every step of the synthesis
- Retro synthesis
- Synthesis that is planned backwards, starting at the target molecule
- Involves breaking up target molecule into simple, available reactant molecules
- Worked Example
- State the reagents and conditions and give suitable equation for the preparation of 3- aminopropan-1-ol from 3 - chloropropanal
- Step 1: draw the structures of the starting material and the product
- Step 2: Use knowledge of functional groups to propose a route
- An alcohol can be made by reducing an aldehyde so 3-chloropropan-1-ol can be made by reducing 3-chloropropanal
Reagents: NaBH4/H20 Conditions: heat
- Halogenoalkanes can be converted to amines using ammonia
Reagents: excess NH3 Conditions: ethanol solvent/reflux
- Synthetic routes in aliphatic chemistry