Lesson32 - The Carbonyls Alpha C-H is Acidic hydrogens O...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Because of the acidity of the α -hydrogen, ketones exist in another, generally less stable form known as ____________ The Carbonyl’s Alpha C-H is Acidic C H 3 C O C H 2 CH 3 α− hydrogens α− carbons O C H 2 CH 3 O H CH 2 CH 3 > 99 % < 1 % H keto tautomer enol tautomer enol tautomer Recall, the larger the pK a , the weaker the acid. The data below shows that of all the C–H bonds, the carbonyl C α –H is the strongest acid. The unusually high acidity of this C-H bond gives it some very important reactivity (e.g., deprotonation of C α -H makes the alpha position a carbon nucleophile). bond CH 3 CH 2 O H CH 3 C O CH 2 H C C CH 3 H H 2 C C H H CH 3 CH 2 H 16 20 25 44 51 pK a
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Interconversion Between Tautomeric Forms is Catalyzed by Acid or Base RCH C H O R H O H H + RCH C H O R H O H H RCH C O R H H 3 O + Acid-catalyzed mechanism of keto-enol interconversion enol tautomer keto tautomer Base-catalyzed mechanism of keto-enol interconversion RCH C H O R HO RCH C O R RCH C O R H O H H + HO + enolate anion enol tautomer keto tautomer
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/25/2012 for the course CHEM 232 taught by Professor Miller during the Spring '08 term at University of Illinois, Urbana Champaign.

Page1 / 9

Lesson32 - The Carbonyls Alpha C-H is Acidic hydrogens O...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online