Quiz 5 Flashcards
What is the difference between enamine and imine formation?
Enamine formation is different in the last proton transfer step that creates the C=C bond of an enamine
LiAlH and NaBH4 are —- —
reducing agents
True or false?
LAH will not reduce carboxylic acids or esters
false, it is strong enough to react with them but NaBH4 is not
The grignard reagent is a — —-
reducing agent
What is necessary to react a carboxylic acid with a grignard reagent?
a blocking group on the acidic proton
Cyanohydrin
CN + OH attatched to the same carbon
Aldehydes + ketones reacted with HCN will yield a —-
cyanohydrin
Wittig Reaction
reduces a ketone to an alkene
C=O bond to C=C bond
How do you form the wittig reagent/ ylide?
P(Ph)3 + alkly halide
pt
- SN2 like process, akyl halide must be primary or secondary
Where does the carbon of the new C=C bond come from in the wittig reaction?
the akyl halide reacting to form the ylide
Bayer Village oxidation
peroxyacetic acid + ketone or aldehyde to form a ester
What is the preference for where the oxygen is moved to for the bayer village reaction?
H>3>2>ph>1> methyl
left: easiest to move right: hardest to move
What is the suffix for compounds with one carb acid?
-oic acid
What is the suffix for compounds with two carb acids?
-dioic acid
What is the suffix for carboyxlate ions?
-oate
Why do carb acids have high bps?
because they can form two hydrogen bonds between each other
In water does the reaction favor a carb acid or H3O+?
carb acid bc it is weaker than H3O+ and reactions favor moving away from the strongest acid
Do halogens stabilize or de stabilize a carb acid?
stabilize, bc they are ewg
alkyne + O3 and H3O+ =
2 carboxlyic acids
primary alcohol + KMnO4/Chromic acid =
carboxylic acid
Reagents and products of oxidation of an alkyl benzene
reagents: chromic acid +H2SO4
products: benzoic acid
R-CN + H3O+ + heat =
carboxylic acid
new way to make carb acids
CO2 + grignard reagent =
carboxlyic acid
a new way to make carb acids
What reagents can be used to reduce a carb acid to an alcohol?
LAH or BH3 . THF and grignard reagent
Mechanism of the reduction of carb acid to an alcohol
- pt to create carboxylate
- Elimination to form aldehyde intermediate
- nuc attack by H-
- pt to create neutral product
Derivatives of carb acids
molecules that look like carb acids but the OH group has been replaced with something else
What are the 5 carb acid derivatives we have been introduced to?
- acid halide
- acid anhydride
- ester
- amide
- nitrile
suffix for acid halide
-yl halide
suffix for acid anhydride
-anhydride
suffix for amide
-amide
Suffix for nitriles
-onitrile
Nucleophilic acyl substitution
nucleophilic attack on a carb acid derivative to replace good LG
What is the intermediate of Nucleophilic Acyl substitution?
tetrahedral intermediate
What charges can form in acidic conditions?
positive or overall neutral
What charges can form in basic conditions?
negative or over all neutral
True or False?
C- and H- make good leaving groups because they are good nucleophiles?
false, they rarely make good leaving groups
Where are the three places an extra pt step can occur in nucleophilic acyl substitution?
- before nuc attack
- between nuc attack and LLG
- after LLG
Why would a pt step occur before nuc attack in nucleophilic acyl substitution?
If the reagents are acidic
Why would a pt step occur between LLG and nuc attack in nucleophilic acyl substitution?
if the LG needs to be protonated in order to leave
Why would a pt step have to occur after LLG?
if the nucleophile was neutral and the final product needs to be neutralized
How do you prepare an acid chloride
treatment of a carb acid with SOCl2
Hydrolysis of acid halides/ anhydrides
acid halide/ anhydride + water = carb acid +HCl
alcoholysis of acid halides/anhydrides
ROH and pyridine + acid halide/anhydride = ester
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Aminolysis of acid halides/ acid anhydrides
2 eq of NH3 + Acid halide/anhydride = amide
Why is pyridine not used in aminolysis of acid anhydrides/halides?
Bc NH3 is strong enough to neutralized HCl on its own
Reduction of acid halides/ acid anhydrides
acid halide/anhydride + LAH or grignard reagent = alcohol
What does LiAl(OR)3H do?
in a reduction of a acid halide/anhyrdie with LAH it will stop it at the aldehyde intermediate
What does the Gilman reagent/R2CuLi do?
in the reduction of an acid halide/acid anhydride with a grignard reagent it will stop it at the ketone intermediate
