10/31 Flashcards
under what conditions can nucleophillic addition undergo
acidic and basic
what is the first step in the general mechanism of nucleophilic addition in basic conditions
the negative nucleophile attacks the carbonyl
what is an addition reaction
two reagents come together to form one product
what is the first step in the general mechanism of nucleophilic addition in acidic conditions
protonate the alcohol to make a better electrophile at the carbonyl carbon
when protonating a carbonyl in nucleophilic addition, what happens to the carbonyl
it is now activated
under acidic conditions what is the charge on the nucleophile
it is not charged, it is neutral
under basic conditions what is the charge on the nucleophile
it is negatively charged
why is the protonated ketone activated?
the resonance structure has a full blown positive carbon
whats a primary difference in nucleophilic addition in acidic and basic conditions
in basic conditions, the nucleophile attacks immediately without protonation initially
in acidic conditions, the carbonyl must be protonated first in order to activate it
when comparing ketones and aldehydes, do their mechanisms differ?
no, only their reactivity
which is more reactive, aldehydes or ketones? why?
aldehydes are more reactive than ketones due to steric and electronic effects
what is the steric effect on aldehydes and ketones
aldehydes are less sterically hindered than ketones so they are more available for nucleophilic attack
what is the electronic effects on aldehydes and ketones
the alkyl groups on the ketone provide electron density into the partially positive carbonyl carbon, this makes it lower in energy and more stable so it is less likely to react
the lack of alkyl groups on an aldehyde make it less stable and higher in energy, so it is more likely to react
in hydration what is the nucleophile
it is water
what is the product of hydration
it is a hydrate or gem diol
