3.9 Organic Synthesis

This question is about reaction profiles using chloroalkanes

For the reaction profile outlined in Fig. 2.1, state the mechanism or type of reaction for each step.

1-chlorobutane      Compound G      Compound H

 Fig. 2.1

Step 2 is carried out by heating under reflux.

Identify Compound H.

1-chlorobutane can be produced from an alkene.  Identify the alkene and give the reagent required.

Explain how the functional group of the final compound in the reaction scheme in part (a) would be different if 2-chlorobutane was used as the starting compound.

Using the information given, state the name of compound Y.

Deduce the structural formula of compound W and explain how compound Z is formed in the reaction.

Compound X will oxidise to compound Y if allowed to fully oxidise. Explain how a student could stop the full oxidation of compound X. 

Deduce the formula of an isomer of compound X that will not react with acidified potassium dichromate, H⁺ / K₂Cr₂O₇.

A series of reactions based on butan-1-ol is shown is Fig. 2.1.

Fig. 2.1

Suggest a suitable reagent and conditions for reaction 1.

Give the structural formulae of U and V.

Suggest a suitable reagent and conditions for reaction 3.

Some reactions of compound A are shown in Fig. 3.1.

Fig. 3.1

Draw the skeletal structures of compounds B, C and D

State the colour change when compound D is formed.

Compound A reacts with iodine and sodium hydroxide ions to give two products. Draw the skeletal structures of these two products.

State the name of compound A.

The reaction scheme shows three steps to synthesise 2-hydroxy-2-methylpropanenitrile.

Propene

Propan-2-ol

Compound G

2-hydroxy-2-methylpropanenitrile

Name the type of mechanism that occurs in

• reaction 1
  
• reaction 3

State the reagents and conditions required for 

• reaction 1
• reaction 2

Draw the mechanism that occurs in reaction 3

Explain why 2-hydroxy-2-methylpropanenitrile does not exhibit optical isomerism.

The following reaction pathway in Fig. 5.1 is used to produce compounds A and B, which when reacted together, form a branched ester molecule, compound C. 

Suggest suitable reagents and conditions for the synthesis of compound A via step 1 and give the name for this type of reaction.

Fig. 5.1

In order for the ester to be produced, the ketone in part (a) must be converted to another compound, B.

Outline how ethanol can be synthesised from ethane in two steps. State the reaction conditions and reagents and name the type of reaction taking place.

The four step synthesis to form propan-1-ol from a ketone is outlined below in Fig. 5.2.