Chemistry 9701 · AS & A Level · Organic synthesis

Organic synthesis — practice question

Liquids that include molecules of T have a lemon scent. The structure of T is shown in Fig. 3.1.
(a)[2]

Molecules of T occur as a pair of stereoisomers. Name the type of stereoisomerism shown by molecules of T. Explain your answer.

(b)[2]

Two organic products are made when a sample of T is heated under reflux with excess acidified concentrated KMnO$_4$. Draw the structures of the two organic products from this reaction in the boxes.

(c(i))[1]

Identify a reagent that is suitable for reaction 1.

(c(ii))[2]

Identify the reagent together with the conditions needed for reaction 2.

(c(iii))[3]

Suggest which product formed in reaction 2 has the higher yield. Explain your answer.

(d(i))[3]

Predict the observations for each test-tube. Explain your answer using the functional groups in Q and R.

(d(ii))[2]

When $\text{PCl}_5(s)$ is added to separate samples of Q and R at room temperature, both react vigorously. Complete the equation shown in Fig. 3.4 to show the reaction that takes place when R reacts with $\text{PCl}_5(s)$.

(d(iii))[2]

Suggest why the samples of Q and R need to be dried before $\text{PCl}_5$ is added. Include an equation that supports your answer.

Worked solution & mark scheme

This 17-mark question has a full step-by-step worked solution and mark scheme. One marking point: States that the compound is optically active

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