Chapter 12

Question 1

What is a phenol?

Answer 1

a benzene + alcohol

Question 2

What is a alkoxide?

Answer 2

deprotonated form of an alcohol

Question 3

What is needed to form an alkoxide?

Answer 3

strong base
ex. NaH

Question 4

How is acidity in alcohols determined?

Answer 4

Resonance - more resonance = increased acidity
Induction: presence of electron withdrawing groups increases acidity
Solvation: more poorly solvated (bulky)=acidic

Question 5

What is the best way to make a 1 prime alcohol?

Answer 5

SN2

Question 6

What is the best way to make 3 prime alcohols?

Answer 6

SN1

Question 7

What are the three ways to prepare an alcohol from an alkene and which reagents do they use?

Answer 7

• Acid-catalyzed hydration: Dilute H2SO4
• Oxymercuration: 1)Hg(OAc)2, H2O
  2)NaBH4
• Hydroboration: 1) BH3THF
  2)H2O2, NaOH

Question 8

What is the order of oxidation?

Answer 8

alcohol to aldehyde/carbonyl to carboxylic acid

Question 9

What are the common reducing agents?

Answer 9

• NaBH4
• LiAlH4

Question 10

What is a diol compound?

Answer 10

compound with two hydroxyl groups

Question 11

What are the Grignard reagents used to prepare and alcohol?

Answer 11

1)CH3MgBr, Et2O
2)H3O+
(CH3 can be any type of carbon chain)

Question 12

What protects alcohol groups from modification in a Grignard rxn?

Answer 12

TMS (trimethylsilyl group)
TMSCl
———->
Et3N

Question 13

What are the options for the substitution of primary alcohols?

Answer 13

1)Simple substitution: primary alcohol +HBr
2)Catalyzed substitution:
primary alcohol + HCl ZnCl2
———>

Question 14

What are the options for the substitution of primary or secondary alcohols?

Answer 14

1) 2alcohol + TsCl/Pyr +Cl -
- inverts stereochemistry
2)1 alcohol +PBr3—-> OH substituted with Br
3)2* alcohol (SOCl2)/—–> Cl swaps with OH and is inverted

Question 15

What are the methods for forming an alkene from the elimination of alcohols?

Answer 15

• Acid-Catalyzed Elimination:
  3* alcohol (H2SO4)/—>/(delta Heat)
  via E1,
• Base-catalyzed elimination
  TsCl/Pyr + EtONa (strong base)
• E2 mechanism

Question 16

What does the oxidation of 1* alcohol lead to?

Answer 16

Carboxylic acid

Question 17

What does the oxidation of 2* alcohol lead to?

Answer 17

Ketone

Question 18

What does the oxidation of 3* alcohol lead to?

Answer 18

Does not happen bc it would lead to 5 bonds to carbon

Question 19

What are the four types of oxidation reactions?

Answer 19

• Chromium Oxidation
• controlled oxidation
• swern oxidation
• Dess-Martin Oxidation

Question 20

Details of Chromium oxidation?

Answer 20

Reagents
- CrO3 or Na2Cr2O7
- (very strong oxidizers)
- 2* alcohol to ketone
- 1* alcohol is over oxidized to the acid

Question 21

Details of controlled oxidation?

Answer 21

• reagent: PCC/CH2Cl2 (pyridinium chlorochromate)
• stops at aldehyde
• prevents over oxidation

Question 22

Details of stern oxidation?

Answer 22

• Reagents: 1)DMSO, (COCl)2/2)Et3N
• 2* alcohol to ketone

Question 23

Details of Dess-Martin Oxidation?

Answer 23

Reagents: DMP/CH2Cl2
- 1* alcohol to aldehyde

Question 24

What is an ether?

Answer 24

an oxygen connected to two hydrocarbon group

Question 25

What is the oxygen orbital hybridization of an ether?

Answer 25

sp^3 - electronic geometry is tetrahedral

Question 26

What is the molecular geometry of an ether?

Answer 26

bent (2 lone pairs)

Question 27

Intermolecular forces of neat ether

Answer 27

- London forces

Question 28

What is the intermolecular force for ethanol?

Answer 28

hydrogen bonding

Question 29

Why do alcohols have a greater boiling point than ethers?

Answer 29

alcohols have stronger intermolecular forces than ethers

Question 30

What are the common ether solvents and what are their benefits?

Answer 30

- Diethyl Ether - THF - 1,4-Dioxane Benefits: - Relatively unreactive - Low boiling point = easy to remove after a reaction

Question 31

What is a crown ether?

Answer 31

cyclic polyethers that tightly bind metal ions Naming: X-Crown-Y

Question 32

How do ethers interact with metals?

Answer 32

- Oxygen interacts with a metal, often stabilizing the negative charge - metals bind the center of ring by interacting with oxygens - hydrocarbons on the outside of the ring mask the positive charge of the metal

Question 33

How do crown ether produce a stable fluorine?

Answer 33

Crown ethers can produce stable F- to act as a nucleophile in an organic solvents (like benzene) because it overcomes issues of stability and solubility

Question 34

What ion do each of the crown ethers bind? 1) 12-Crown-4 2) 15 -Crown-5 3) 18- Crown-6

Answer 34

1)Li 2)Na 3)K

Question 35

What is Williamson Ether Synthesis

Answer 35

- great for symmetrical and asymmetrical ethers - two step mechanism: Proton transfer and nucleophilic attack - uses a strong base that deprotonates the alcohol includes and alcohol and an alkyl halide

Question 36

What is autooxidation?

Answer 36

- diethyl ether reacts slowly with O2 to form hydro peroxide which reacts violently when heated.

Question 37

What is an expoxide?

Answer 37

cyclic ether with a single oxygen

Question 38

What is an oxirane?

Answer 38

an epoxide that is particularly reactive due to ring strain

Question 39

What are the two common methods for forming epoxides?

Answer 39

1) Peroxy acid addition to an alkene - trans alkene + MCBPA ---->trans epoxide 2) Epoxides via halohydrins - halohydrin is treated with a strong base Ex. NaOH

Question 40

Williamson Ether Synthesis Mechanism

Answer 40

(CH3OH) 1)NaH/2)CH3Br ---> CH3OCH3

Question 41

Why are epoxides more reactive than ethers?

Answer 41

ring strain

Question 42

What are the two kinds of ring-opening reactions?

Answer 42

- reaction with a strong nucleophile - acid-catalyzed ring opening

Question 43

Examples of some strong nucleophiles?

Answer 43

RONa, NaCN, NaSH, RMgBr, LAH

Question 44

When a strong nucleophile reacts with an epoxide ring, which carbon gets the addition of the nucleophile?

Answer 44

the less hindered carbon

Question 45

What happens to the stereochemistry when the ring is opened?

Answer 45

the stereochemistry is inverted

Question 46

If the ring has a primary and a secondary carbon which carbon does the nucleophile attach to?

Answer 46

the primary carbon

Question 47

If the ring has a primary carbon and a tertiary carbon, which carbon does the nucleophile attach to?

Answer 47

the tertiary carbon

Question 48

If the ring the ring has a secondary and a tertiary carbon, which does the nucleophile attach to?

Answer 48

the tertiary carbon