Aldehydes And Ketones Flashcards
What is a carbonyl group?
carbon attached to oxygen with double bond
Where is the carbonyl group present?
aldehydes
ketones
carboxylic acids
What is the functional group of an aldehyde?
RCHO
What is the functional group of a ketone?
RRCO
What can the R groups in aldehydes and ketones be?
alkyl groups
Or
aryl groups
What is the suffix for an aldehyde?
-al
What is the suffix for a ketone?
-one
What ketones are not possible?
those with fewer than three carbons
Are carbonyl groups polar or non polar?
Strongly polar
How is charged distributed in a carbonyl group?
carbon partially positive and oxygen partially negative
Which element in the carbonyl group is more electronegative?
Oxygen
What forces are between carbonyl compounds?
permanent dipole dipole forces
What do dipole dipole forces create for carbonyl compounds?
Higher boiling points than alkanes of comparable relative molecular mass
What is the solubility of carbonyl compounds?
shorter chains mix completely as hydrogen bonds form between oxygen
as carbon chain length increases the compound is less soluble
What is the reactivity of carbonyl compounds?
Difference in electronegativity of strongly polar C=O means nucleophillic reagents attack partially positive carbon
Which reaction occurs with carbonyl compounds?
Nucleophillic Addition
What happens in a nucleophillic addition reaction?
lone pair electrons on nucleophile attack partially positive C
electrons in double bond go to O forming single bond
O has lone pair of electrons and partially negative
O lone pair electrons attracted to H+
OH added to compound
What is hydroxynitrile?
contains both hydroxyl (OH) and nitrile (CN) group
Which is highest priority, nitrile or hydroxyl group?
nitrile
Where do we name hydroxynitriles from?
The nitrile group, including the carbon in a nitrile as the first carbon
What is the symbol for a cyanide ion?
CN-
How does a cyanide ion react with a carbonyl compound?
lone pair electrons of CN- attack carbon partially positive
electrons in C=O move to O
Cyanide added to carbonyl compound
O has lone pair electrons and partially negative
O lone pair electrons attracted to H+
OH added to carbonyl compound
What is produced when a cyanide ion and carbonyl compound react together?
hydroxynitrile and racemic mixture of two optical isomers/enantiometers
Why can nucleophillic addition lead to a racemic mixture?
:CN- ion may attack from above or below the flat C=O group