M4: L-2 Flashcards
What is the rate determining step in addition reactions?
Nucleophile attacks carbonyl carbon
What are the steps of addition reactions with strong nucleophiles?
- nucleophile attacks first and bonds to carbonyl carbons
- electrophile attacks negatively charged oxygen in second step
What are the steps of addition reactions with a weak nucleophile?
- Electrophile attacks first
- nucleophile attacks carbocation
Why are aldehydes more reactive than ketones?
The Carbonyl carbon in ketones is a worse electrophile than in aldehydes
Why is the carbonyl carbon in a ketone less reactive than in aldehydes? (2)
- sterically hindered ( bulky substituents)
- alkyl groups are electron donating and reduction + charge on carbon ( ketones have 2 aldehydes have 1)
What is the result of an addition reaction of an aldehyde wth an alcohol?
Hemiacetal
What is the result of a substitution reaction of a Hemiacetal + an alcohol
Acetal
Are amines stronger or weaker nucleophiles than alcohols?
Stronger
Does an addition reaction of an aldehyde with a 1st degree amide occur in one step or two?
One
What is the result of an addition and then elimination reaction under the same conditions of an aldehyde with an amine?
Imide