Introduction to A Level Organic Chemistry

A list of tests for different organic groups is given in Table 6.1.

Complete Table 6.1 to identify an organic functional group, in aliphatic compounds, that produces a positive result in each test.

Table 6.1

Deduce the functional group present in compound A using both the molecular formulae of A and B and the reaction of B with Fehling's reagent.

Name the type of reaction that occurs in each of the following conversions.

• $\text{A} \rightarrow \text{B}$
• $\text{C} \rightarrow \text{E}$
• $\text{E} \rightarrow \text{F}$

Use the information in Table 6.2 and the molecular formulae to deduce structures for G and H. Draw your structures in Fig. 6.1.

Use the information in Table 6.2, the molecular formulae and your answer to (b)(iii) to deduce structures for A, C, D, E and F. Draw your structures in Fig. 6.1.

On the diagram of abscisic acid, use an asterisk (*) to label each chiral carbon atom.

Abscisic acid is reacted with an excess of $\text{NaBH}_4$.

Give the molecular formula of the organic product formed.

Draw the skeletal formula of the carbon-containing product with the largest molecular mass.

Identify the carbon-containing product with the smallest molecular mass. Explain how this product arises.

Identify the third carbon-containing product of this reaction by giving its displayed or structural formula.

Use the experimental results in the table above to determine the group(s), in addition to the benzene ring, present in the four isomers W, X, Y and Z.

Complete the table below, identifying the group(s) present in each isomer.

Use the information in (a) to suggest a structure for each of these isomers and draw these in the boxes.

Draw a circle around the chiral centre in one of the above structures.

Suggest the structures of compounds T and U and draw them in the boxes above.

Suggest reagents and conditions for steps 1-5.

• step 1:
• step 2:
• step 3:
• step 4:
• step 5:

What types of reaction are steps 1 and 5?

• step 1:
• step 5:

The compound diborane, $\text{B}_2\text{H}_6$, can be used as a rocket fuel.
It can be prepared by the reaction of boron trifluoride, $\text{BF}_3$, with sodium borohydride, $\text{NaBH}_4$.

Balance this equation.

Primary and secondary alcohols can be formed by the reaction of carbonyl compounds with $\text{NaBH}_4$, which is a source of hydride ions, $\text{H}^-$.

Complete the mechanism for the reaction of butanone with hydride ions, $\text{H}^-$, and draw the intermediate in the box. Include all necessary curly arrows and relevant dipoles.

Suggest the type of reaction in step 1.

The diol Y can be prepared by the same method.

Draw the structure of the diene which could be used to prepare diol Y.

Describe the structure of and bonding in benzene, $\text{C}_6\text{H}_6$.

In borazine, $\text{B}_3\text{N}_3\text{H}_6$, the boron and nitrogen atoms alternate around the ring. Each ring atom has a single hydrogen atom bonded to it.
All boron-nitrogen bonds in borazine are $0.144\text{ nm}$ in length, whereas in simple compounds $\text{B}-\text{N}$ and $\text{B}=\text{N}$ bond lengths are $0.154\text{ nm}$ and $0.136\text{ nm}$ respectively.

Suggest and draw the structure of borazine.

Suggest a possible identity for each reagent L, M and N.

L ..........................................................................................................................................

M .........................................................................................................................................

N .........................................................................................................................................

Give the structure of the organic product formed when M reacts with butanal.

What is observed when N reacts with butanone?

What type of reaction is occurring when N reacts with butanone?

Suggest a mechanism for the reaction of butanal with $\text{CH}_3^-$ ions. Include all necessary curly arrows, lone pairs and relevant dipoles.

A chemist decides to prepare the following organic compound G from butanal.

Draw the structure of the organolithium reagent which could be used to prepare G from butanal.

sodium,

bromine water,

alkaline aqueous iodine.

Suggest structures for V and W.

State the type of stereoisomerism shown by compound V and draw the structures of the stereoisomers.

type of stereoisomerism:

structures of stereoisomers:

Suggest the structure of the neutral compound X.

sodium,

Fehling's solution.

The result of the bromine test shows a functional group is absent from compound J. Suggest the identity of this functional group.

In the boxes below, draw three possible straight-chain structures for J that fit the above results, and that are structural isomers of each other.

Which functional group does this reaction show that J contains?

Which of your three structures K, L or M contains this group and is therefore J?

Name the type of stereoisomerism shown by J.

Draw two structures of J to illustrate this stereoisomerism.

What is the molecular formula of methoxetamine?

On the diagram above, circle any chiral centres that are present in methoxetamine.

Name two functional groups in methoxetamine, in addition to the aryl group.

In the table, complete the structure of each of the compounds formed when methoxetamine is reacted with the following reagents.

State the type of reaction in each case.