Aldehydes and Ketones Flashcards
The C and O double bond is…
Highly polar with a partial negative charge on the oxygen and a partial positive charge on the carbon. They are considered polar and aprotic
Acidity of alpha carbon
ketones have 2
aldehydes have 1
-the hydrogens are weakly acidic and can be removed
-aldehydes are more acidic
When forming resonance, where does the negative charge want to go?
to the oxygen
-when the negative charge is on the alpha carbons, it becomes more reactive
Boiling points
aldehydes and ketones have a lower boiling point compared to carboxylic acids and alcohols
The carbonyl carbon
is electrophilic with its partial positive charge
The alpha carbon
Functions as a nucleophile after the acidic hydrogen is removed. is negatively charged
Redox reactions
LEO -lose electrons -gain bonds to oxygen -lose hydrogen bonds GER -gain electrons -lose bonds to oxygen -gains hydrogen bonds
In order to oxidize an aldehyde…
We are going from an aldehyde to a carboxylic acid and a strong oxidizing agent is needed
In order to oxidize a ketone…
Cannot be oxidized into a carboxylic acid
In order to reduce an aldehyde or ketone…
goes to alcohol using hydride base reducing agents
Addition reactions
Hydration reaction
Hydration reaction
Water adds to carbonyl carbon via nucleophilic addition. becomes a hydroxyl group (geminal diol)
When treated with an alcohol
Forms hemiacetal or hemiketal
Cyanohydraide formation
Cyanohydrine formed
