Indietro
Problema 2a
Give an example for each of the following:
a. a β-keto nitrile
Problema 2b
Give an example for each of the following:
b. a β-diester
Problema 2c
Give an example for each of the following:
c. a β-keto aldehyde
Problema 3
Explain why a base can remove a proton from the α-carbon of N,N-dimethylethanamide but not from the α-carbon of either N-methylethanamide or ethanamide.
Problema 4
Explain why the -hydrogen of an N,N-disubstituted amide is less acidic (pKa = 30) than the -hydrogen of an ester (pKa = 25).
Problema 5a
Rank the compounds in each of the following groups from strongest acid to weakest acid:
a.
Problema 5c
Rank the compounds in each of the following groups from strongest acid to weakest acid:
c.
Problema 6
Explain why 92% of 2,4-pentanedione exists as the enol tautomer in hexane but only 15% of this compound exists as the enol tautomer in water.
Problema 7d,e
Draw the enol tautomers for each of the following compounds. For compounds that have more than one enol tautomer, indicate the one that is more stable.
d.
e.
Problema 7f
Draw the enol tautomers for each of the following compounds. For compounds that have more than one enol tautomer, indicate the one that is more stable.
f.
Problema 10
A ketone undergoes acid-catalyzed bromination, acid-catalyzed chlorination, racemization, and acid-catalyzed deuterium exchange at the ⍺-carbon. All of these reactions have similar rate constants.What does this tell you about the mechanisms of these reactions?
Problema 11a
Show how the following compounds can be prepared from the given starting material:
a.
Problema 14a
How could each of the following compounds be prepared from a ketone and an alkyl halide?
a.
Problema 14b
How could each of the following compounds be prepared from a ketone and an alkyl halide?
b.
Problema 16a
How could each of the following compounds be prepared from cyclohexanone?
a.
Problema 16b
How could each of the following compounds be prepared from cyclohexanone?
b.
Problema 17a
Describe how the following compounds could be prepared from cyclohexanone using an enamine intermediate:
a.
Problema 17b
Describe how the following compounds could be prepared from cyclohexanone using an enamine intermediate:
b.
Problema 18a
Draw the products of the following reactions:
a.
Problema 18b
Draw the products of the following reactions:
b.
Problema 19a
What reagents should be used to prepare the following compounds?
a.
Problema 19b
What reagents should be used to prepare the following compounds?
b.
Problema 19c
What reagents should be used to prepare the following compounds?
c.
Problema 20a
What aldol addition product is formed from each of the following compounds?
a.
Problema 20b
What aldol addition product is formed from each of the following compounds?
b.
Problema 24
How could you prepare the following compound using a starting material that contains no more than three carbons?
Problema 25a
Describe how the following compounds can be prepared using an aldol addition in the first step of the synthesis:
a.
Problema 25b
Describe how the following compounds can be prepared using an aldol addition in the first step of the synthesis:
b.
Problema 25c
Describe how the following compounds can be prepared using an aldol addition in the first step of the synthesis:
c.
Problema 26
What two carbonyl compounds are required for the synthesis of morachalcone A, via a Claisen–Schmidt condensation?
<IMAGE>
