Enols and Enolates Flashcards Preview

CHY1101 - Organic chemistry > Enols and Enolates > Flashcards

Flashcards in Enols and Enolates Deck (16)
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1
Q

Chemistry involving enols and enolates happens where?

A

On the carbon next to the double bond

2
Q

What does tautomerism mean?

A

Intramolecular proton transfer

Moved from one part of a molecule to another

3
Q

What is an enol?

A

A molecule with C=C bond with an OH group joined directly to it

4
Q

What is enolization?

A

The conversion of a carbonyl compound into its enol

5
Q

Why is the enol less stable than the ketone?

A

Enols bond swaps are unfavourable

C=O and C-H which is 1160 to C=C and O-H which is 1120

6
Q

What can enol formation be catalysed by?

A

Both base and acid

7
Q

Is it faster to form an enol by base or acid?

A

Base

8
Q

Do enols and enolated act as electrophiles or nucleophiles?

A

Nucleophiles as they are electron rich

9
Q

What can the enol-type species enamine (Draw it) be formed by?

A

an electophilic imine

10
Q

What can the enol-type species nitronate (draw it) be formed by?

A

Nitro alkane

Et3N (base)

11
Q

What are some examples of stable enols?

A

1,3-dicarbonyl compounds as there is increased conjugation

Ph-enol - enol form is aromatic and therefore much more stable

12
Q

Why do reactions occur through the carbon and not the C=O?

A

In order to keep the stable C=O

13
Q

What condition is needed for enolate alkylation?

A

Strong base with a pKaH value higher than the pKa of the carbonyl compound

14
Q

What base is usually used for enolate alkylation and why?

A

LDA (Lithium diisopropylamide)

Has large isopropyl groups added as it needs to act as a base but not the nucleophile so it wont attack the C=O

15
Q

What is the aldol reaction?

A

Enolates reacting with aldehydes and ketones to form an adol product

16
Q

What reagents are needed to replace C=O with C=C?

A

Ph3P-CH2

Et2O