Topic 26: Carbonyl Group Flashcards
Carbonyl group
C=O
Aldehyde
Contains carbonyl group on the end (hyde) (hidding on the end)
Ketone
Contains carbonyl group NOT on the end
Aldehyde nomenclature
alkanal
eg pronanal
butanal
Never numbers as always on end
Ketone nomenclature
alkanone
eg propanone
pentan-2-one
Number as can be anywhere in middle of chain
Aldehydes oxidise into
Carboxylic acids
Ketones oxidise into
Nothing… they don’t oxidise
Test for aldehyde/ ketone
Tollens reagent creates silver mirror when reacts with aldehyde, NOT ketones
Tollens reaction
[Ag(NH3)2]^+ reduced to Ag
Primary alcohol oxides to ____ oxides to ____
aldehyde - carboxylic acid
Reduced the otherway as well
Secondary alcohol oxidises to ____ oxides to ____
Ketone - NOTHING
Reduced the other way as well
Reducing agent of carbonyl group compounds
NaBH4
Sodium Tetrahydridoborate
Name of mechanism for carbonyl group
Nucleophilic addition
Where does :H- come from
NaBH4
Drawing mechanism using aldehyde and ketone
Arrow from :H- or :-CN to carbon
Arrow from double bond to O
New molecule
:O- attached still
Arrow from lone pair on O to H+
Makes alcohol or hydroxynitrile
e.g. 2-hydroxybutanenitrile or 2-hydroxy-2-methybutanenitrile
Carboxylic acids
Weak acids - dissociate incompletely
Carboxylic acid + sodium carbonate
reaction
CH3COOH+ Na2CO3 CH3COONa + CO2 + H2O
Esters functional group
R-COO-R
Naming esters
Methyl ethanoate
1st bit comes from
Forming esters
Esterification/ Hydrolysis
Carboxylic acids and alcohols
Equ’m mixture with strong acid catalyst H+.
Glycerol
Very soluble in water used in toothpaste
Acyl chloride
R-COOCl
Acid anhydride
−C(=O)−O−C(=O)−
Naming acyl chlorides
alkanoyl chlorides
propanoyl chloride
Naming acid anhydrides
Alkanoic anhydrides
Ethanoic anhydride
Properties of acyl chlorides
React quickly
Violent reaction
Produces steamy white fumes of HCl toxic gas
Properties of acid anhydrides
Cheaper
Less corrosive
Less vigorous
Only carboxylic acids
Nucleophilic addition elimination mechanism
Arrow from nucleophile to carbon
Arrow from double bond to oxygen
New molecule
:O-
Positive nucleophile
Arrow from lone pair on O to CO bond
Arrow from CL bond to L
Arrow from bond to positive nucelophile
Makes carboxylic acid among other things
Mechanism of acyl chlorides and acid anhydrides name
Nucleophilic addition elimination
Produced from primary amine and acyl chloride
N-substituted amide
Reaction of acid anhydride and methanol
Ethanoic acid and methy ethanoate
Produced from acyl chloride and ammonia
Amide
Nucleophiles in nucleophilic addition elimination
H2O: , alcohol, ammonia and primary amines
