11/7 Flashcards
for hydrate formation, what is the nucleophile
water
for acetal formation, what is the nucleophile
alcohol
for imine formation, what is a nucleophile
primary amine
for enamine formation, what is the nucleophile
secondary amine
for cyanohydrin formation, what is the nucleophile
cyanide ion
whats a good application of cyanohydrins
creates carbon-carbon bonds
why must we use a different method of creating a cyanohydrin other than HCN
HCN is a weak acid, it is a weak source of the cyanide ion nucleophile
- equilibrium favors formation of reactants
-does not dissociate all the way
how can we accelerate the formation of a cyanohydrin
use an ionic source like NaCN as a source of nucleophile
what are the reagents for cyanohydrin formation
1) NaCN and H2SO4
why are wittig reactions important
they make carbon carbon bonds
what is a phosphorus ylide
it is the reagent for a wittig reaction
it has a positive and negative charge on the same molecule
the negative charge on the carbon is the nucleophile
what is the overall transformation in a wittig reaction
a aldehyde or ketone is transformed into an alkene
what do we need to do for the reagents in a wittig reaction
the triphenyl phosphine needs to be generated in situ
what happens to the oxygen on the carbonyl in the wittig reaction
it becomes a byproduct to make triphenylphosphine oxide
how do you prepare a phosphorous ylide
react triphenyl phosphine with a 1° or 2° alkyl halide and a base like n-butyllithium or potassium t-butoxide
