11/19 Flashcards
what does a reaction with a nitrile under basic conditions form
a carboxylate salt ammonia and a regeneration of base
what are the conditions of decarboxylation
a carboxylic acid under heat will form a alkane and CO2 as a byproduct
what type of mechanism is a decarboxylation?
concerted and cyclic
what is the intitial product of a decarboxylation
it forms an enol which tautonomerizes into a ketone
what type of isomers are keto-enol tautomers
they are constitutional isomers of eachother formed by rearrangement
which is more stable? the enol or keto tautomer
the keto
whats an enol and enolate
an enol is an alcohol bonded to a double bonx, an enolate is a deprotonated enol
what is special about the alpha position on a carbonyl
it is acidic with a pka of 20, it can be deprotonated
why is an alpha proton more acidic than a regular alkane proton
it is resonance stabilized and forms an enol upon deprotonation
what is the keto-enol equillibrium relationship
equilibrium favors the keto form
under basic conditions, what is the first step in enolization of a carbonyl
deprotonate the alpha carbon
what intermediate is formed in base-catalyzed enolization
the enolate which is then protonated to form an enol and the original base catalyst
whats the first step in acid catalyzed enolization
protonate the cabornyl
what occurs in alpha halogenation
the alpha proton is substituted with a halogen
what attacks the halogen in alpha halogenation
the pi bond electrons come out and take the halogenation and form a bond at the alpha position
