Extending the carbon chain length

What are the two methods to extending the carbon chain length?

Cyanide ion+haloalkane, HCN (nitrile) +carbonyl compounds

What is cyanide?

Ion (NaCN, KCN), inorganic chemical

What is the mechanism, are the reagents and conditions for using cyanide with haloalkanes

Nucleophilic substitution

NaCN/KCN (ethanolic)

Heat under reflux

Why can’t water be present when reacting cyanide with haloalkanes?

OH- would be nucleophile instead of CN-

What is the mechanism and reagent for HCN with carbonyl compounds?

Nucleophilic addition, HCN

What conditions would be used in reality for he reaction between HCN and carbonyl compounds?

aq cyanide with slightly acidic conditions (to form HCN)

What does the reaction between HCN and carbonyl compounds give?

Hydroxy nitrile compound

Curly arrow mechanism for nucleophilic addition of HCN

Cyanide ion attaches to carbon, electrons from double bond goes to oxygen (polar bond)

O- is protonised by another HCN

Examples of reactions of nitriles

Reduction to form amines (H2 (or LiAlH4) and Ni catalyst)

Hydrolysis to form carboxylic acids (strong acid, heat under reflux)