Chapter 18

Question 1

Answer 1

Question 2

What is the mechanism for nucleophilic addition under basic conditions?

Answer 2

Question 3

What is the mechanism for nucelophilic addition under acidic conditions?

Answer 3

Question 4

Give the reagents necessary to transform each of the following starting materials
into 2-phenylethan-1-ol.

(Ph)CH=CH₂

Answer 4

Question 5

Give the reagents necessary to transform each of the following starting materials
into 2-phenylethan-1-ol.

Answer 5

1. LiAlH₄
2. H₃O+

Question 6

Give the reagents necessary to transform each of the following starting materials
into 2-phenylethan-1-ol.

Bromobenzene

Answer 6

1. Mg, Et2O
2. Ethylene oxide (epoxide)
3. H3O

Question 7

Propose syntheses of the following compounds starting from alcohols with 4
carbons or less.

2-Heptanol

Answer 7

Note: You can make the necessary epoxide by dehydration of propanol followed by oxidation with m-CPBA.

Question 8

Propose syntheses of the following compounds starting from alcohols with 4
carbons or less.

1-Butanethiol

Answer 8

Question 9

Propose syntheses of the following compounds starting from alcohols with 4
carbons or less.

2-Hexanol

Answer 9

Question 10

Propose syntheses of the following compounds starting from alcohols with 4
carbons or less.

** 2-Hexanone - CH3CO(CH2)3CH3**

Answer 10

1. PBr3
2. Mg, Et2O
3. Acetaldehyde
4. H3O+
5. CrO3, aq. H2SO4

Question 11

Propose syntheses of the following compounds starting from alcohols with 4
carbons or less.

2-Methyl-1,2-propanediol

Answer 11

Question 12

Propose syntheses of the following compounds starting from alcohols with 4
carbons or less.

2,2-Dimethylpropanal - (CH3)3CCHO

Answer 12

Question 13

Propose syntheses of the following compounds starting from alcohols with 4
carbons or less.

Hexanoic acid - CH3(CH2)4CO2H

Answer 13

Question 14

Dess Martin Reaction (Periodinane)

Answer 14

Question 15

Give reagents that accomplish the following transformation.

Answer 15

1. PBr₃
2. ((CH₃)₂CH)₂CuLi Gilman reagent

Question 16

Give reagents that accomplish the following transformation.

Answer 16

1. H2, Lindlar’s Catalyst
2. O3; Zn, H3O+

Question 17

Give reagents that accomplish the following transformation.

Answer 17

1. BH₃, THF
2. H₂O₂, aq. NaOH
3. NaH
4. CH₃CH₂CH₂Br

Question 18

Give reagents that accomplish the following transformation.

Answer 18

1. NaOtBu, tBuOH
2. mCPBA
3. NaOMe, MeOH
4. NaH; MeI

Question 19

What happens when you react TMSO with PCC?

Answer 19

Compound A is oxidized using PCC and then reacted with methyl magnesium bromide,
CH3MgBr, to form Compound B.

http://pages.towson.edu/jdiscord/www/332_answer_keys/Chapters_17_and_19/PracticeExam1AnsKey.pdf

Question 20

What are the reagents used to protect an alcohol before reacting Grignards?

How do you unprotect it after the reaction?

Answer 20

Protect with: 1. Me₃SiCl, Et₃N

De-protection: H₃O+

Question 21

How do you reduce a ketone or aldehyde into an alkane?

(Clemmenson Reaction)

Answer 21

Zn(Hg)/
HCl, H2O

Question 22

What is the product?

Answer 22

Question 23

What is the mechanism for cis diol formation from and alkene?

Answer 23

Question 24

What is the reagent for cleaving an expoxide to yield trans diols?

Answer 24

Question 25

What reagents cleave an epoxide to yield cis diols?

Answer 25

Question 26

How do you reduce esters to alcohols?

Answer 26

Question 27

How do you add Br to the benzylic position a the end of CH3 in Ph-CH3?

Answer 27

Question 28

Answer 28

Question 29

Answer 29

**Claisen rearrangement** followed by **Diels-Alder** *Tautomerization of the Claisen product to a phenol does not take place because no H is available to dontate to the Oxygen.*