Organic Chem reactions / reagents Flashcards
reagent to oxidize a primary alcohol to an aldehyde?
PCC, all other oxidizing agents will go to carboxylic acid;
reagent to oxidize a secondary alcohol to a ketone?
jones reagent or chromium reagents such as Na2Cr2O7
What does NaBH4 do?
reduces ketones / aldehydes to alcohols
what does LAH (LiAlH4) do?
reduces carboxylic acids to alcohols
R-Br + Mg forms?
R-Mg-Br = Grignard reagent which is a powerful nucleophile. these attack carbonyl centres and add alkyl groups. Acid work up is required to protonate the oxygen.
NaCN reacting with a ketone yields?
addition of the CN group and protonation via an acid to get an OH group.
called a cyanohydrin
Reacting an aldehyde with R-NH2 and acid makes?
an imine which is a carbon double bonded to a nitrogen which has some R group attached to it.
Reacting an aldehyde / ketone with R-NH2 and acid makes?
an imine which is a carbon double bonded to a nitrogen which has some R group attached to it.
note: primary amine must attack
if a secondary amine attacks we get an enamine which is a C=C-NR2 group
what is decarboxylation?
add heat to a compound with a carboxylic acid and CO2 will be kicked off
Acid catalyzed esterification? (Fischer esterification)
reacting a carboxylic acid with acid and alcohol to create an ester
CO2H + H+ primes the carboxylic acid
then CO2H2 is attached by R-OH and the H deprotonates after
What occurs when you have a C triple bonded to an N and you add H3O+ (Acid)
C triple bond N converts to a carboxylic acid
What reaction is this?
NH4Cl and NaCN are added to an aldehyde
this is followed by the addition of H3O+ to form ____?
Strecker synthesis which forms amino acids. The R group attached to the initial aldehyde determines the amino acid.
What reaction is this?
NH4Cl and NaCN are added to an aldehyde
this is followed by the addition of H3O+ to form ____?
Strecker synthesis which forms amino acids. The R group attached to the initial aldehyde determines the amino acid.
what is the enolate anion?
a deprotonated carbonyl species which exhibits resonance.
What is Keto-Enol tautomerism? which is more stable
when enolates are formed, the electrons can form a carbon = carbon double bond and shift the carbonyl double bond away to form an alcohol. (Enol). The double bond C = O can reform and break the C=C bond to form a ketone (keto)
keto is more stable
what are mesylates and tosylates?
They replace the H on OH groups and make alcohols inert in reactions. They are also great leaving groups. Note addition of the TsCl or MsCl retains stereo but Sn2 after inverts it.
what occurs if a strong base deprotonates the alpha hydrogen of an imine?
the electrons shift to break the imine C=N bond and rather form an enamine.
LDA vs. NaOH in the de-protonation of the alpha hydrogen in aldol reactions?
LDA - kinetic product
NaOH - thermo product
cold temperature also promotes kinetic product.
If you see a reaction where it shows an aldol condensation product with (-H2O) what comes next?
dehydration reaction in which the OH group is removed and a C=C bond is made (this occurs with heat and acid)
T or f, in nucleophilic addition reactions a pi bond breaks and two sigma bonds are made. A elimination reaction shows 2 sigma bonds break while a new pi bond is made.
true! a nucleophilic substitution would show the addition of one sigma and the loss of another.
what is a nucleophilic addition - elimination reaction?
when a nucleophile attacks a carbonyl species and breaks the C=O pi bond. Then reformation of the pi bond kicks off the most appropriate LG. Similar to substitution but in two steps. (Sn1 is 2 steps but different mechanism)
What is made when a carboxylic acid reacts with an alcohol and acid?
an ester
R-CO2H + R-OH —> RC(=O) - OR
hydrolysis of esters: adding acid to an ester makes? What about reacting an ester with another ester in acid?
carboxylic acid forms if you expose an ester to H3O+
if you expose an ester to acid in the presence of another ester, the ester will attack the protonated ester and cause transesterification (the ester group changes it’s R group)
Saponification produces what?
base catalyzed ester hydrolysis which creates carboxylate anion. You must protonate it to form the carboxylic acid.
