31.1- SYNTHESIS ROUTES

Question 1

What can you do using the organic reactions you have already met?

Answer 1

can work out reaction scheme to convert starting material into target molecule

Question 2

What is important in maximising the yield of the target?

Answer 2

keep number of steps as small as possible

Question 3

What can oxidise primary alcohols to aldehydes, and aldehydes to carboxylic acids?

Answer 3

potassium dichromate, acidified with dilute sulfuric acid

Question 4

What are secondary alcohols oxidised to?

Answer 4

ketones

Question 5

What will sodium tetrahydridoborate (III), NaBH4 reduce and will not reduce?

Answer 5

reduce C=O but not C=C

Question 6

Where can sodium tetrahydridoborate (III), NaBH4 be used?

Answer 6

in aqueous solution

Question 7

Why does sodium tetrahydridoborate (III), NaBH4 reduce polar unsaturated groups such as Cδ+ = Cδ-, but not non-polar ones, such as C=C?

Answer 7

as it generates the nucleophile :H- which attacks Cδ+ but is repelled by the electron-rich C=C

Question 8

What is hydrogen with a nickel catalyst, H2/Ni used to reduce and not what?

Answer 8

C=C but not C=O

Question 9

What can tin and hydrochloric acid, Sn/H+ be used to reduce?

Answer 9

may be used to reduce R-NO2 to R-NH2

Question 10

How can alcohols be converted to alkenes?

Answer 10

by passing their vapours over heated aluminium oxide or by acid-catalysed elimination reactions

Question 11

Examples of important reactions of aromatic compounds using benzene as the starting material?

Answer 11

nitrobenzene -> phenylamine

acyl-substituted benzene