11. Oxidized Alcohols Reactivity with Aldehydes and Ketones Flashcards
what suffix do aldehydes have?
-al
what suffix do ketones have?
-ones
what is the electrophilic part of a carbonyl?
the carbon
which is more reactive, aldehydes or ketones and why?
aldehydes are more reactive because the hydrogen beside the carbonyl makes it more susceptible to reaction
describe a nucleophilic addition reaction.
when a nucleophile attacks the carbon of a carbonyl
what do nucleophiles attack on a carbonyl and why?
the carbon because it is electrophillic
what type of solvent are Grignard reactions done in and why?
non-protic solvents because Grignard reagents are very reactive so they need this solvent to stabilize the reaction
what is cyanohydrin?
and OH and CN groups bonded to a carbon of interest
describe the reaction with a carbonyl and a HCN.
the carbonyl is protonated to OH and a CN group is added to the same carbon
what are the steps for a Grignard reagent reaction?
- bring the pi bond from the carbonyl to the oxygen and give the oxygen a negative charge
- count the carbons in the Grignard molecule and add that amount of carbons to the carbon of interest in the other molecule (the one with the negative charge oxygen)
what are oxygen nucleophiles usually in the form of?
alcohol or water
why are reactions with weak nucleophiles reversible?
The weak nucleophile is less likely to attack the electrophile, making the formation of the product less favoured. As a result, the reaction is more likely to reverse and revert to the original reactants.
describe a hemi acetal.
a chiral center with an RO, OH group at the top and an H, and R group
describe a hemiketal.
a chiral center with two R groups at the bottom and an OR and OH group at the top
describe an acetal.
a chiral center with two OR groups at the top, and a H and R group at the bottom
describe a ketal.
two OR groups at the top, and two R groups at the bottom
what does it mean if H3O+ is added to a reaction?
there is an acid catalyst in the reaction
what is a commonality between acetals and ketals?
they have two OR groups attached to a chiral center
what is the nucleophile in hydrate formation?
water
what is the job of an acid in hydrate formation?
speed up water molecules combining to form hydrates
describe a general hydrate formation reaction.
a molecule with a carbonyl turns into two hydroxyl groups
what two things need to react in acetal formation?
aldehydes reacting with alcohol nucleophiles
what is the intermediate in acetal formation?
hemiacetals
describe an acetal formation reaction with an acid catalyst.
the carbonyl in a molecule turns into an OH and OR group as the intermediate then the final product is the carbonyl turning finally into two OR groups
what is the intermediate in ketal formation reactions?
a hemi ketal
describe a ketal formation reaction with an acid catalyst.
the carbonyl in a molecule turns into an OH and OR group as the intermediate then the final product is the carbonyl turning finally into two OR groups
what is the product when an acetal is hydrolyzed with water?
an aldehyde
what is the product when a ketal is hydrolyzed with water?
a ketone
are the hemi forms of acetals and ketals stable?
no
describe the general mechanism of a reaction with an oxygen nucleophile.
a carbonyl turning into two OR groups
why are ketals and acetals commonly used as protecting groups?
because they are easy to add and take off by adding acid or water
describe the general reaction of acetals and protecting groups.
one of the carbonyls in a molecule turns into two lone oxygens that are connected
describe a general synthesis of hydrolysis of amines reaction with acid and MeNH2.
the carbonyl of a molecule turns into an NHCH3 and OH group as the intermediate then you are left with a single NHCH3 double-bonded group plus water
describe a general imine formation reaction.
the carbonyl of a molecule turns into a double-bonded NR group plus water
describe the general reaction of hydrolysis acetal reaction with acid and MeNH2.
the two lone oxygens bonded to the same carbon turn into a carbonyl
describe a general imine hydrolysis reaction with HCl.
a molecule with a double-bonded NR group plus water turns into a carbonyl plus the R groups and HCl
what are enamines formed from in terms of amines?
secondary amines
