20.2 Synthetic Routes

The following reaction pathway 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.

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

Name and draw the structure of the molecule that is produced from Step 2.

Give the name of the type of reaction that is involved in Step 2 and suggest suitable reagents and conditions for the process.

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.

Give the names of four possible substances A to D
 

Give the reagents and conditions for Step 4.

Propanal is a versatile organic building block used in the synthesis of plastics and rubber chemicals.

Propanal can be produced from propanoic acid in the following two-step reaction. 

	Step 1		Step 2
Propanoic acid		Propan-1-ol		Propanal

State the reaction type, including suitable reagents, for Steps 1 and 2.

 

Suggest why it is not possible to convert propanoic acid directly to propanal using the reagent you identified for Step 1 in (a).

Explain why Step 2, in (a), is completed by distillation.

Identify, explain your reasoning, which of the three organic compounds, from the reaction scheme in (a), would be distilled first.

State four factors that should be considered when designing a reaction scheme for the synthesis of a target molecule in industry.

1-(3-Aminophenyl)ethanol can be synthesised according to the following three-step reaction scheme.

Step 1 involves a reaction at position 3 of the benzene ring of 1-phenylethan-1-one. 
 

State the reaction type, including suitable reagents, for Step 1.

State a suitable reagent for Step 2, in (b).

In Step 3 of the reaction scheme from (b), compound C is heated with hydrochloric acid in the presence of a tin catalyst to form the final product, 1-(3-aminophenyl)ethanol. 

Explain why Step 3 is a reduction reaction.

Suggest a reaction scheme, using displayed formulae, that could be used to prepare a sample of propyl propanoate. 

Conditions and reagents are not required.

One of the intermediates in the reaction scheme, from (a), has a molecular mass of 74.09 g mol^-1.
 

State suitable reagents and conditions required to form this intermediate. 

Describe how you could test that this intermediate has been formed.

Propanal and the intermediate (M_r = 74.09) in the reaction scheme, from (a), are to be separated by distillation.

Explain which chemical will distil first.

One of the intermediates in the reaction scheme, from (a), has a molecular mass of 60.09 g mol^-1. 

State suitable reagents and conditions required to form this intermediate. 

Using Section 26 of the Data Booklet, describe how you could prove that this intermediate has been formed without reversing the reaction.