CHEMSHEETS ALDEHYDES KETONES www chemsheets co uk A

ALDEHYDES methanal propanal 3 -methylbutanal © www. chemsheets. co. uk A 2 1049 2

KETONES propanone butanone pentan-3 -one 4 -methylpentan-2 -one © www. chemsheets. co. uk A

OXIDATION & REDUCTION © www. chemsheets. co. uk A 2 1049 2 -June-2016

OXIDATION & REDUCTION • Tollen’s reagent, contains [Ag(NH 3)2]+ • Used to test for

OXIDATION & REDUCTION • Fehling’s solution, contains Cu(+2) • Used to test for aldehydes

OXIDATION & REDUCTION • Acidified potassium dichromate, contains Cr 2 O 72 • Used

OXIDATION & REDUCTION Distillati on Reflux Aldehyde condenses back into reaction mixture and reacts

NUCLEOPHILIC ADDITION + – • Addition reactions: atoms add across C=O to the C

NUCLEOPHILIC ADDITION Reduction with Na. BH 4 © www. chemsheets. co. uk A 2

NUCLEOPHILIC ADDITION e. g. ethanal + Na. BH 4 © www. chemsheets. co. uk

NUCLEOPHILIC ADDITION e. g. propanone + Na. BH 4 © www. chemsheets. co. uk

NUCLEOPHILIC ADDITION Reaction with KCN then acid © www. chemsheets. co. uk A 2

NUCLEOPHILIC ADDITION • many hydroxynitriles contain chiral C • formed as racemic mixture (50/50

© www. chemsheets. co. uk A 2 1026 25 -May-2016

NUCLEOPHILIC ADDITION e. g. propanone + KCN then acid © www. chemsheets. co. uk

NUCLEOPHILIC ADDITION e. g. propanal + KCN then acid © www. chemsheets. co. uk

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CHEMSHEETS ALDEHYDES & KETONES © www. chemsheets. co. uk A 2 1049 2 -June-2016

ALDEHYDES methanal propanal 3 -methylbutanal © www. chemsheets. co. uk A 2 1049 2 -June-2016

KETONES propanone butanone pentan-3 -one 4 -methylpentan-2 -one © www. chemsheets. co. uk A 2 1049 2 -June-2016

OXIDATION & REDUCTION © www. chemsheets. co. uk A 2 1049 2 -June-2016

OXIDATION & REDUCTION • Tollen’s reagent, contains [Ag(NH 3)2]+ • Used to test for aldehydes – gives silver mirror • Reduced from Ag(+1) to Ag(0)

OXIDATION & REDUCTION • Fehling’s solution, contains Cu(+2) • Used to test for aldehydes – gives brick-red precipitate of Cu 2 O • Reduced from Cu(+2) to Cu(+1)

OXIDATION & REDUCTION • Acidified potassium dichromate, contains Cr 2 O 72 • Used to test for alcohols (1 y and 2 y) & aldehydes – goes from orange Cr 2 O 72 - to green Cr 3+ • Reduced from Cr(+6) to Cr(+3)

OXIDATION & REDUCTION Distillati on Reflux Aldehyde condenses back into reaction mixture and reacts further Alcohols and carboxylic acids (have hydrogen bonds between molecules) have higher bpts than aldehydes – so aldehyde can be

NUCLEOPHILIC ADDITION + – • Addition reactions: atoms add across C=O to the C and O • C is + so attacked by nucleophiles (electron pair donors) • The three atoms attached to the C are planar © www. chemsheets. co. uk A 2 1049 2 -June-2016

NUCLEOPHILIC ADDITION • many hydroxynitriles contain chiral C • formed as racemic mixture (50/50 mixture of enantiomers) • as equal chance of attack from above & below plane © www. chemsheets. co. uk A 2 1026 25 -May-2016

NUCLEOPHILIC ADDITION e. g. propanal + KCN then acid © www. chemsheets. co. uk A 2 1026 25 -May-2016