Flashcards
7. Enols & Enolates
Cards in this deck (24)
- 1What is tautomerism?Shift between two structure forms
- 2What is enolate?Deprotonated alcohol (OL) conjugated to alkene (ENE)
- 3Is keto-enol tautomerism equilibrium or resonance?Equilibrium because bonds between H and C/O are being made and broken
- 4When you enolize a non-symmetrical ketone, which product is the thermodynamically stable one?The one that results in the double bond with the most substituted ends
- 5Which product is the thermodynamic one and which is the kinetic one when you enolize a non-symmetric ketone?LDA and other hidnered amide bases deprotonate the less hindered site, resulting in the kinetic product
Deprotonation at the more hindered site gives you the thermodynamic product - 6How do you enolize an ester?Use the O-R as the base because if it were to do carbonyl attack you get the starting material
- 7Rate of enolization easeSame as nucleophilicity/basicity
- 8How do you enolze an acid chlorideYou don't
Cl can act as a LG and give a ketene - 9How do you enolize carboxylic acid?In presence of base you just get deprotonation because carboxylic acid is more acidic
- 10How do you enolze an amide?1° and 2°: No (pKa of proton on the N is much lower and you'll get a negative charged nitrogen)
3°: Noice! (since there's no protons to get deprotonated) - 11'enolizable' imine and enamiens**
- 12How do you enolize nitroalkanes and nitriles?Pretty easily
- 13What helps make an enol thermodynamically stable?Conjugation via dicarbonyls (e.g. dimedone)
- 14Harp modification whatever**
- 15—https://www.youtube.com/watch?v=HgzGwKwLmgM
- 16nitrosation of enols**
- 17What are two kinds of stable enolate equivalents?Lithium enolates and silyl enol ethers
- 18Does enolation via lithium give kinetic or thermodynamic enolate?kinetic
- 19mechanism of lithium enolate**
- 20mechanism of silyl enol ether formation**
- 21What kind of electrophiles are compatible for this? Is this a hard or soft site?Hard
- 22hydrolysis of enol ethers**
- 23Slide 43**
- 24Slikde 44**
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- Chemistry Flashcards on 7. Enols & Enolates, created by John Rivada on 22/04/2019.
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- John Rivada
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