1. CHAPTER 18 KETONES AND ALDEHYDES
PROBLEMS 1,3,4,6,7-11,12C
15,17,19,20,24,27A,C,31,33,34A,B,D,35A,C,39A-E,45A,B,51A-D,61,65,66

2. CARBONYL COMPOUNDS CONTAIN A C=O GROUP IMPORTANT MEMBERS ALDEHYDE
KETONE
CARBOXYLIC
ACID
ESTER
ACID
CHLORIDE
AMIDE
CHAPTER 18
CHAPTER 20
CHAPTER 21

3. STRUCTURE OF THE CARBONYL GROUP
NOTE: NUC ATTACK
OCCURS AT PI ORBITAL
NOT BACKSIDE OF C=O
CHAPTER 22

4. KETONES: ALKANONE, MUST NUMBER TO GIVE CARBONYL LOWEST NUMBER
NOMENCLATURE
IUPAC SYSTEM
KETONES: ALKANONE, MUST NUMBER TO GIVE
CARBONYL LOWEST NUMBER
5,5-DIMETHYL-3-HEXANONE
(5,5-DIMETHYLHEXAN-3-ONE)
BUT
4-HYDROXY-2-BUTANONE
3-OXOBUTANOIC ACID

5. ALDEHYDES - IUPAC ALDEHYDE CARBON IS NUMBERED “ONE” 3-ISOPROPYLHEXANAL6 4 2 1 5 3 6 2 4 3 5 1
3-ISOPROPYLHEXANAL
FORMYLCYCLPENTANE
3-ISOPROPYL-5-OXOHEXANAL

6. ALDEHYDES COMMON NAMES
STEM PLUS ALDEHYDE
HCHO
HCO2H
FORMALDEHYDE
FORMICA - ANTS
FORMIC ACID
CH3CHO
CH3COOH
ACETALDEHYDE
ACETUM - SOUR
ACETIC ACID
CH3CH2CHO
CH3CH2CO2H
PROPIONALDEHYDE
PROTOS PION - FIRST FAT
PROPIONIC ACID
CH3CH2CH2CO2H
CH3CH2CH2CHO
BUTYRALDEHYDE
BUTRYM - BUTTER
BUTYRIC ACID
CH3CH2CH2CH2CH2CHO
CH3CH2CH2CH2CH2CO2H
CAPROALDEHYDE
CAPER - GOAT
CAPROIC ACID

7. Ketones common names NAME RADICALS IN ALPHA ORDER + KETONE
RADICAL SYSTEM
NAME RADICALS IN ALPHA ORDER + KETONE
Methyl phenyl ketone
STEM CONVENTION - ALKYL METHYL KETONES
NAME STEM OF ALKYL GROUP ACCORDING tTO THE PREVIOUS SLIDE FOLLOWED BY PHENONE
ACETOPHENONE
Write the structure for butyrophenone

8. SPECTROSCOPY OF ALDEHYDES AND KETONES
2. NMR Read pp
1. IR READ PAGE 780
MASS SPECTRA
ALPHA CLEAVAGE
TWO ACYLIUM IONS ARE ABOUT THE SAME
THEREFORE
ETHYL RADICAL IS MORE STABLE THAN METHYL
RADICAL STABILITY CONTROLS FRAGMENTATION

9. McLAFFERTY REARRANGEMENT
CHARACTERISTICS
A GAMMA HYDROGEN IN THE PARENT CATION-RADICAL IS TRANSFERRED
TO CARBONYL OXYGEN ATOM INTRAMOLECULARLY
CLEAVAGE OF ALPHA-BETA CARBON (WITH RESPECT TO C=O
OCCURS
A STABLE ALKENE IS LOST AND A NEW RESONANCE STABILIZED CATION RADICAL(ENOL) IS FORMED
NOTE- THE PARENT CATION, STABLE ALKENE LOST, AND
THE NEW STABILIZED CATION RADICAL HAVE EVEN MOLECULAR MASSES

10. EXAMPLE g a b
Even mw
Even mw

11. MECHANISM OF McLAFFERTY REARRANGEMENT
THERE IS A NICE SUMMARY ON BOTTOM OF PAGE 784. LOOK IT OVER.

12. REVIEW OF SYNTHESIS OF KETONES AND ALDEHYDES
OXIDATION OF ALCOHOLS - LAST SEMESTER
OZONOLYSIS OF ALKENES - LAST SEMESTER
FRIEDEL ACEYLATION AND GATTERMAN KOCH
WILL BE COVERED ON NEXT TEST
HYDRATION OF ALKYNES - LAST SEMESTER
HYDROBORATION AND OXIDATION - LAST SEMESTER

13. 1,3-DITHIANE METHOD Dream up a mechanism for this reaction.
PREPARATION OF 1,3-DITHIANES
Dream up a mechanism for this reaction.

14. WHY HIGH ACIDITY OF 1,3-DITHIANES?
Old explanation
Vacant d-orbitals
Modern explanation s*
Thus

15. Synthetic Methodology
1. Deprotonation of 1,3-dithiane with n-BuLi
2. Alkylation or dithane anion (SN2)
R must be methyl or primary
R can not be Ar, CH2=CH
3. Hydrolysis of alkylated dithiane.

16. Preparation of Ketones via 1,3-dithianes
INSTEAD OF STOPPING AT MONO-ALKYLATION STEP, ONE CAN REPEAT PROCESS USING THE REMAINING ACIDIC HYDROGEN ATOM

17. UMPOLUNG OF C=O
"acyl anion equivalent"

18. Retrosynthetic analysis
Prepare 1-phenyl-2-pentanone
HSCH2CH2CH2SH
n-BuLi
n-BuLi
PhCH2B
CH3CH2CH2Br
hydrolysis