Organic Synthesis

Question 1

Answer 1

Electrophilic addition
Conc H3PO4 Catalyst
Steam
60-70 ATM of pressure
200-450 degrees

Question 2

Answer 2

Elimination
Conc H2SO4 Catalyst
Under Reflux

Question 3

Answer 3

Hydrogenation
H2
Nickel Catalyst

Question 4

Answer 4

Elimination
KOH
Hot & Ethanoic Conditions

Question 5

Answer 5

Electrophilic Addition
HX (Where x = Halogen)
20 Degrees

Question 6

Answer 6

Free Radical Substitution
X2 (where x is a halogen)
UV Light

Question 7

Answer 7

(Don’t need at this level)
Elimination
XBr

Question 8

Answer 8

Nucleophilic Substitution
KOH
Cold and Aqueous

Question 9

Answer 9

Nucleophilic Addition (Reduction)
NaBH4 or LiAlH4 Reducing agents

Question 10

Answer 10

Oxidisation
H+ or Acidified Potassium Dichromate

Question 11

Answer 11

Oxidisation
H+ or Acidified Potassium Dichromate

Question 12

Answer 12

Esterification
:OH - (alcohols)
Strong Acid Catlayst

Question 13

Answer 13

Esterification
Acid Anhydride or Acyl Chloride
String Acid catalyst

Question 14

Answer 14

Nucleophilic Addition Elimination
:OH- (alcohols)

Question 15

Answer 15

Nucleophilic Addition Elimination (Hydrolysis)
H2O

Question 16

Answer 16

Nucleophilic Addition Elimination
:NH3 or Amines

Question 17

Answer 17

Nucleophilic Addition Elimination
Acid Anhydride or Acyl Chloride

Question 18

Answer 18

Nucleophilic Subsitiution
KCN
Aqueous Ethanoic Conditions

Question 19

Answer 19

Nucleophilic Addition
H2 Nickel Catalyst
or
LiAlH4

Question 20

Answer 20

Nucleophilic Subsitution
Excess Conc :NH3
Ethanoic
Heat with Sealed System/Container

Question 21

What is Organic Synthesis

Answer 21

Using reaction mechanisms to create a target molecule

Question 22

Why is it preferable to create a molecule with as little steps as possible

Answer 22

To improve the % yield of the Product

Question 23

What Could Cause the yield of an individual step to be low? (2)

Answer 23

Chemicals are lost when transferring between containers - some product could be left in the refraction mixture each time

Incomplete/ reversible reactions

Question 24

What are the two main dehydrating agents used?

Answer 24

Al2O3 (Vapours pass over it)

Acid-Catalysed elimination (Strong acid catalysts)

Question 25

What does a smoky flame when burnt suggest

Answer 25

High C:H ratio
(possibly aromatic)

Question 26

What are the 3 main reducing agents used?

What do they Reduce?

Answer 26

NaBH4 —> Reduces C=O (Hydride H- attacks delta positive carbon)
H2/Ni Catalyst —-> Reduces C=C
HCl/Tin + small amount of NaOH—-> Reduces NO2 to NH2

Question 27

Name the Mechanism/Reaction Type, reactants and conditions

Answer 27

Electrophilic Substitution

Question 28

Name the Mechanism/Reaction Type, reactants and conditions

Answer 28

Reduction

Question 29

Name the Mechanism/Reaction Type, reactants and conditions

Answer 29

Nucleophilic addition Elimination

Acid Anhydride or Acyl Chloride

Question 30

Name the Mechanism/Reaction Type, reactants and conditions

Answer 30

Electrophilic substitution

AlCl3 Catalyst

Acyl Chloride or Acid anhydride

Question 31

Name the Mechanism/Reaction Type, reactants and conditions

Answer 31

Question 32

Name the Mechanism/Reaction Type, reactants and conditions

Answer 32

Question 33

How would you test for Acyl Chloride

Answer 33

Add Water,

White misty fumes of HCl

Question 34

Describe the differences with an OH- acid and OH- Alcohol infrared spectra

Answer 34

OH- acid has its lowest point of the broad peak below 3000cm^-1 (and a C=O sharp peak)

OH- alcohol is more rounded and has its peak above 3000cm^-1

Question 35

Explain how you would synthesise the following amine, with methylbenzene as your starting molecule

Answer 35

Step 1 : Use FRS to form Bromo-methylbenzene
Br2 and UV light

Step 2: Nucleophilic substitution of KCN alcoholic and aqueous conditions

Step 3: H2/Nickel catalyst (Reduction)