Synthetic routes

Question 1

What is acidified potassium dichromate(VI) an example of?

Answer 1

oxidising agent

Question 2

What is the formula for acidified potassium dichromate and what is it acidified with?

Answer 2

• K₂Cr₂O₇
• w/ dilute sulfuric acid

Question 3

What does acidified potassium dichromate oxidise>?

Answer 3

• primary alcohol - aldehyde
  
  • aldehyde - carboxylic acids
• secondary alcohol - ketone

Question 4

What will sodium tetrahydrioborate(III) (NaBH4) reduce?

Answer 4

• C=O
• but not C=C
• used in aq soln
• reduces polar unsaturated groups but not non polar oens
• this is because it generate the :H- nucleophile which attacks the partically positive carbon
• repelled by the high electron density in C=C

Question 5

How is C=C reduced?

Answer 5

hydrogen with a nickel catalyst H2 / Ni

will not reduce C=O

Question 6

How is R-NO2 reduced to R-NH2?

Answer 6

tin and hydrochloric acid, Sn/H+

Question 7

How are alcohols dehydrated?

Answer 7

• alcohols can be converted to alkenes by passing their vapour over heated aluminium oxide
• or by acid-catalysed elimination reaction

Question 8

How can propanoice acid be synteisised from 1 bromopropaane~?

Answer 8

• write down all the compound which can be made from 1-bromopropae and all those from which propanoic acid can be made
• can be converted to propan-1-ol which can be converted to propanoic acid
• to produce the alcohol
  
  • reflux with NaOH
• to produce the carboxylic acid from propan-1ol
  
  • reflux with acidified potassium dichromate

Question 9

How is propylamine synthesised from ethene?

Answer 9

• ethene to bromoethane
  
  • using HBr
• bromoethane to propanenitrile
  
  • using KCN / dil. H2SO4
• propanenitrile to propylamine
  
  • Ni/H2