Chapter #6 Flashcards
(25 cards)
Can a ketone be a terminal functional group?
no, never
what is a synonym for:
- butyraldehyde
- valeraldehyde
butanal
pentanal
what is the common name for 2-butanone
ethylmethylketone
how do you commonly name ketones?
two alkyl groups in alphabetical order followed with ‘ketone’
do alcohols or aldehydes/ketones have more polar dipoles and how does this affect boiling point?
even though aldehydes and ketones have more polar dipoles, alcohols still have a higher boiling point because of Hydrogen bonding.
are aldehydes or ketones more reactive and why?
aldehydes tend to be more reactive because there is less steric hindrance and fewer electron donating alkyl groups.
how are aldehydes and ketones produced?
aldehydes: from the single oxidation of a primary alcohol (using PCC)
ketones: oxidation of a secondary alcohol using anything (no fear of going anywhere past here)
if there is no good leaving group present (as in the case of aldehydes and ketones), then after nucleophilic attack, the carbonyl double bond _____
will not close and the O- will likely be protonated
if there is a good leaving group present (as in the case of carboxylic acids and their derivatives), then after nucleophilic attack, the carbonyl double bond _____
will close and the leaving group will leave.
aldehyde + water
geminal diol
ketone + water
geminal diol
aldehyde + alcohol
hemiacetal
how do you form an acetal from an aldehyde
add 2 equivalents of alcohol
how do you get from hemiacetal to acetal
SN1 reaction in anhydrous acid
hydroxyl group is protonated and leaves as water which leaves a carbocation ready to be attacked by the alcohol nucleophile
how is an imine formed
react aldehyde or ketone with an amine
what is the name of the compound formed via the reaction between aldehydes/ketones and HCN
cyanohydrines
what is the name for the reaction between an amine and a aldehyde or ketone?
condensation reaction (dehydration)
what happens in a reaction of PCC and an aldehyde
nothing
compare lithium aluminum hydride and sodium borohydride
LiAlH4 vs. NaBH4
NaBH4 is often used when milder conditions are needed
what is the prefix used for aldehydes in rings
When the -CHO functional group is attached to a ring the suffix -carbaldehyde is added, and the carbon attached to that group is C1.
what is the name of the reaction of alcohol and ketone/aldehyde
hemiacetal formation, nucleophilic addition
what is the name of the reaction of an alcohol with hemiacetal/hemiacetal
nucleophilic substitution
aldehydes/ketones + amines (or amine-based derivitives) to form
imines
why are hemiacetals and hemiketals shortlived?
the -OH group will rapidly become protonated in acidic conditions and is lost as water, leaving behind a carbocation that is very susceptible to attack by an alcohol. Once the alcohol has been added, the acetal or ketal becomes more stable because the newly added group is less likely to become protonated and leave as compared to -OH.
