Organic Synthesis
No description yet. This curated deck is ready for daily study.
Card preview (24)
How can you maximise the yield of the target molecule?
Keep the number of steps in the organic synthesis as small as possible.
What is yield?
A measure of the efficiency of the conversion of a starting material into a product and the atom economy of a process.
How do you know if a reaction with a cyanide ion is needed?
If the number of carbons in the chain increases.
What kind of agent is acidified potassium dichromate?
Oxidising agent.
How is potassium dichromate acidified?
Using dilute sulfuric acid.
What does acidified potassium dichromate oxidise?
Primary alcohols -> aldehydes -> carboxylic acids. Secondary alcohols -> ketone
What kind of agent is NaBH4?
Reducing agent
What does NaBH4 do?
Reduces C=O (polar) into a C-OH but not C=C (non polar). It can be used in aqueous solution.
Why can NaBH4 reduce C=O but not C=C?
It produces :H^- which attacks C (in C=O) but is repelled by the electron rich C=C.
What can reduce C=C?
Hydrogen with a nickel catalyst. It can’t reduce C=O.
What can reduce R-NO2 into R-NH2?
Tin and hydrochloric acid.
How can alcohols be converted into alkenes?
By passing their vapours over heated aluminium oxide or by acid-catalysed elimination reactions.
How can you go from 1-bromopropane to propanoic acid?
1) 1-bromopropane to propan-1-ol. (reflux with NaOH aqueous) 2) Propan-1-ol to propanoic acid. (reflux with acidified potassium dichromate)
How can ethene be converted into propylamine?
1) Ethene to bromoethane using HBr 2) Bromoethane to Propanenitrile using KCN. 3) Propanenitrile to propylamine using hydrogen with a Nickel catalyst.
Why can’t you test for a fluoroalkane using silver nitrate?
AgF is soluble in water.
How to form a haloalkane from an alkane?
Free radical substitution UV light X-X
How to form a primary amine from a haloalkane?
Nucleophilic substitution Primary haloalkane reacting with ethanolic NH3.
How to form a nitrile from a haloalkane?
Nucleophilic substitution Ethanolic KCN
How to form a secondary/tertiary/quaternary amine from a haloalkane?
Nucleophilic substitution Non-primary haloalkane with ethanolic NH3.
How to form a primary amine from a nitrile?
Reduction LiAlH4
How to form an alkene from a haloalkane?
Elimination using ethanolic KOH under reflux.
How to form a haloalkane from an alkene?
Electrophilic addition H-X
How to form a dihaloalkane from an alkene?
Electrophilic addition X-X Room temperature
How to form an alkene from an alcohol?
Elimination/Dehydration Conc H2SO4/H3PO4 catalyst