04/23/24 Flashcards
Electrophillic addition
follows markovnikov addition where the hydrogen adds to the less substituted carbon and the halogen adds to the more substituted carbon
what is the reasoning behind markovnikovs rule
it is driven by carbocation stability, if we add a hydrogen to the less substituted carbon, it leads to the formation of a more stable carbocation
if we treat an alkyne with lindars catalyst and H2, what is the product
a cis alkene
when we treat a alkene with hydrogenation, what happens to the saturation
the alkene is unsaturated, the alkane is saturated
what is zaitsevs rule
when dealing with E2 Eliminations, it is the formation of the more substituted alkene as the major product
what is a regioselective reaction
it is when a certain region is favored in a reaction
what is prochiral
it is one step before a chiral carbon
what is the stereoselectivity of a electrophillic addition
there is no stereoselectivity, the halogen can add from above or below in the empty p orbital of the sp2 carbonation
what is the stereochemical result of an electrophilic addition
it is a racemic mixture of enantiomers
what reaction is an electrophillic addition similar to?
it is similar to an SN1 mechanism due to the formation of a racemic mixture through the addition to a carbocation
what are the key features of an electrophilic addition?
the key features are
formation of the most stable carbocation
markovnikov regioselectivity
no steroselectivity: 50/50 racemic mix
what is anti-markovnikov
anti-Markovnikov is the addition of the halogen to the less substituted carbon on the alkene
what is the result of an electrophillic addition with a peroxide
it is an anti-markovnikov addition where the hydrogen adds to the more substituted carbon and the halogen adds to the less substituted carbon
why do we see anti-markovnikov with an electrophilic addition with peroxide
this mechanism goes through a radical intermediate
by adding a free radical halogen to the less substituted carbon, another radical will form in a more stable location
what are the three ways to hydrate an alkene
through acid-catalyzed hydration ( rearrangements)
oxymercuration demercuration (no carbocation, no rearrangement)
hydroboration oxidation (anti markonikov)
