The structure of the compound known as thalidomide can be shown as: Copy the molecule and label the chiral centre on your drawing.

Chiral carbon is the carbon that has all its four valencies satisfied by four different atoms or groups of atoms. This chiral centre makes a compound optically active. The chiral centre in thalidomide is shown below.

The structure of the compound known as thalidomide can be shown as: Name two functional groups found in a molecule of thalidomide.

Thalidomide has several functional groups including two ketone groups, two amide groups, a cyclohexane and a cyclopentane. The major functional group is amide which is represented by - CONH .

The flow charts below show how poly(ethene) can be obtained by two different routes. Identify substance A and give the equation for the reaction taking in process 1 .

Process 1 is the thermal cracking of decane, a saturated hydrocarbon which is heated up to 600 ° C - 700 ° C and its vapours then passed from silica or either alumina. This process breaks the covalent bond in the saturated hydrocarbon resulting in the mixture of alkanes and alkenes. Thermal cracking of decane produces ethene and octane. So the substance A is octane.

The flow charts below show how poly(ethene) can be obtained by two different routes. Give the term used to describe process I.

Decane, a saturated hydrocarbon which is heated up to 600 ° C - 700 ° C , and its vapours are then passed from silica or either alumina. This process breaks the covalent bond in the saturated hydrocarbon resulting in the mixture of alkanes and alkenes. Thermal cracking of decane produces ethene and octane. This process is called thermal cracking.

The flow charts below show how poly(ethene) can be obtained by two different routes. Name substance B and give the equation for the reaction taking place in process 3 .

Since in process 3 , a water molecule is removed from the reactant to give ethene. Ethanol is dehydrated in the presence of sulphuric acid to give ethene. Sulphuric acid acts as a dehydrating agent in this reaction. The reaction is as follows: C 2 H 5 OH → sulphuric acid C 2 H 4 + H 2 O Substance B is ethanol.

The flow charts below show how poly(ethene) can be obtained by two different routes. Give the term use to describe process 3 .

Since in process 3 , a water molecule is removed from ethanol to give ethene. Hence, the reaction is a dehydration reaction. Common dehydration reaction uses dehydrating agents, like sulphuric acid and alumina.

HARD

AS and A Level

IMPORTANT

Earn 100

Explain how $2$ -aminopropanoic acid can be prepared from lactic acid in two steps. You should give the reagents and conditions necessary plus balanced symbol equations for the reactions taking place.

Important Questions on Organic Synthesis

HARD

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 29 - Organic Synthesis>DESIGNING A DRUG>Q •

Discuss how molecular modelling has helped in the search for new and improved medicinal drugs. Think about the method used to determine the structure of HIV protease.