1. Section 2c CHEM 222 Coursepack

2. Alcohol Synthesis
Organolithium and Grignard reagents deliver alkyl anion to C  O
Acidic workup provides the alcohol

3. Alcohol Oxidation to Carbonyl
Oxidation of 1° alcohols makes aldehydes
Oxidation of 2° alcohols makes ketones
3° Alcohols cannot be oxidized!

4. Oxidation Reagents Chromium trioxide (CrO3) in pyridine
Sodium chromate (Na2CrO4) or sodium dichromate (Na2CrO7) in H2SO4 (Jones Oxidation)
MnO2 is effective at making aldehydes
HNO3 and KMnO4 good for making carboxylic acids
DMSO and oxalyl chloride, (COCl)2, good at generating aldehydes (Swern Oxidation)

5. Oxidation Examples

6. 2) HO-(CH2)2-OH /trace H3O+ 3) SOCl2 4) H3O+ 5) ClCOCH2CH2CH3
List the reagents in the correct order to form compound A, from compound B. (Not all reagents needed)
1) PCC
2) HO-(CH2)2-OH /trace H3O+
3) SOCl2
4) H3O+
5) ClCOCH2CH2CH3
6) MgBr-(CH2)2-CH3/diethylether
7) Na2Cr2O7/H2SO4
Correct Answer: 21641

7. The following methods are all acceptable methods
of forming ketones EXCEPT:
A) Oxidation of secondary alcohol
B) Reduction of carboxylic acid
C) Ozonolysis of tetrasubstituted alkene
D) Friedel crafts acylation
E) Both B and C
Correct Answer: B

8. Which reagent would cause 1-butanol to be oxidized to butanal?
A) PCC B) Na2Cr2O7, H2SO4
C) O3 D) LiAlH4
Correct Answer: A

9. Organometallic Reagents (cont.)
The Mg atom in a Grignard reagent is a strongly Lewis acidic site. It is usually stabilized by an ether solvent:
The formation of a Grignard reagent involves a radical mechanism: 9

10. Organometallic Reagents (cont.)
The C atom attached to the metal in Grignard reagents and organolithium reagents has a lot of negative charge on it. It is a strong Brønsted base and can deprotonate water: 10

11. Organometallic Reagents (cont.)
This reaction can be used to label specific sites with deuterium:

12. Which solvent would not be appropriate to prepare a Grignard reagent in?
A) CH3OH B) Et2O (ether)
C) H2O D) Both A and C
Correct Answer: D

13. Organometallic Reagents
Organometallic reactions are irreversible
Organocuprates (R2CuLi) good reagents to displace halides
Organocuprates made from organolithium compounds and copper iodide

14. Example of R2CuLi Reaction

15. Solvents in Organic Chemistry
Solvents can play a key role in the properties of the solutes dissolved in them. The stronger solvent-solute interaction for methoxide versus t-butoxide is a reason that the latter is a stronger base: 15

16. Solvents in Organic Chemistry (cont.)
A variety of polar solvents are commonly used in organic chemistry. They are classified as polar protic if they can engage in hydrogen bonding and polar aprotic if they cannot.

17. Solvents in Organic Chemistry (cont.)
The saying “like dissolves like” reminds us that polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes. 17

18. Solvents in Organic Chemistry (cont.)18

19. Solvents in Organic Chemistry (cont.)
Consider possible intermolecular interactions, i.e., between a polar solvent and an ionic compound:
Stronger interactions lead to better solubility!

20. Solvents in Organic Chemistry (cont.)
A polar solvent can also dissolve polar organic compounds if there are strong enough intermolecular interactions between solvent and solute, like hydrogen bonding: 20