AS/A2 Conditions, Reagents and Reactions

AS Organic Reactions

Free Radical Substitution (Alkane to Haloalkane)

Initiation --> Propagation --> Termination

Conditions: UV Light

e.g. 

Br₂ à 2Br^.

CH₃ + Br^. à CH₂^. + HBr

CH₂^. + Br₂ à CH₂Br + Br^.

2Br^.à Br₂

 

Nucleophilic Substitution (Haloalkane to Alcohol/Nitrile/Amine)

Conditions: Warm haloalkane in:

- Aqueous NaOH or KOH

- Ethanolic KCN

- Ethanolic Ammonia

e.g.

 

Elimination (Haloalkane to Alkene)

Conditions:

·         Warm haloalkane in ethanolic hydroxide ions

·         Heat under reflux

e.g.

 

Nucleophilic Addition (Aldehyde to Hydroxynitrile/Alcohol)

Conditions:

·         KCN for Hydroxynitrile

·         Aqueous NaBH₄ for Alcohol

e.g.

This is also known as the reduction of an aldehyde or ketone when a primary or secondary alcohol is produced (SEE BELOW).

 

Reduction of Aldehydes and Ketones (Aldehyde/Ketone to Alcohol)

Equations:

R-COH + 2[H] à R-CH₂-OH

R-COR + 2[H] à R-CH-(OH)-R

 

Electrophilic Addition (Alkene to Haloalkanes/Alkyl Hydrogensulphates)

Conditions:

·         Hydrogen halides used

·         Also reacts with Bromine and Conc. Sulfuric Acid

·         Major product produced due to stability of carbocation

 

Production of Ethanol

·         Hydration of Alkenes

Conditions:

- Steam

- 300^oC and 60atm pressure

- H₃PO₄ acid catalyst

 

·         Fermentation

Conditions:

- Glucose and Yeast

- Anaerobic conditions

- 30-40^oC

- Separated by fractional distillation

 

Fermentation is being increasingly used because it is a renewable biofuel, and is almost Carbon Neutral. However, there are some concerns attached…

 

A2 Organic Reactions

 

Esterification (Carboxylic Acid to Ester)

Conditions:

·        …