3.3.14-Organic Synthesis

Question 1

What needs to be thought of in organic synthesis

Answer 1

• Reagents required
• Presence of other functional groups
• conditions required
• rate of reaction
• yield
• atom economy
• Costs , plants, chemicals
• safety, toxicity, flammability
• problems of purification
• possibility of optical activity

Question 2

Problems of chiral compounds

Answer 2

May not be as effective -higher dosage

Cause dangerous side effects

Question 3

Consequences of chiral compounds

Answer 3

Isomers have to be separated to obtain effective result
Separation can be expensive and complicated
Non separation lead to larger dosage being used cause side effects

Question 4

Solutions to chiral compounds

Answer 4

Use natural chiral compounds as starting
Use reactions that give specific isomers
Catalysts to give specific isomers
Enzyme or bacteria which are stereoselective

Question 5

Thermal cracking reaction

Answer 5

Alkane to alkanes,alkenes

Need high T,high P

Question 6

Catalytic cracking reaction

Answer 6

Alkane to alkenes and branched alkanes

High T , zeolite

Question 7

Complete combustion

Answer 7

Alkanes to water and carbon dioxide

Need excess O2

Question 8

Reaction of free radical substitution

Answer 8

CH4 to CH3Cl +HCl

Cl2 UV light

Question 9

Alkene reaction hydrogenation

Answer 9

H2/Ni 150C

C2H4 to C2H6

Question 10

Alkene reaction with Br2

Answer 10

C2H4 to CH2BrCH2Br

Br2 room temp
Electrophilic addition

Question 11

Alkene reaction with HBr

Answer 11

C2H4 to CH3CH2Br

HBr room temp
Electrophilic addition

Question 12

Alkene reaction with conc H2SO4

Answer 12

Alkene to CH3CH2-O-SO3H

Electrophilic addition
Conc H2SO4

Question 13

Alkene reaction with H2O

Answer 13

C2H4 to CH3CH2OH

H3PO4 ,high T , high P
Hydration

Question 14

What is the reaction when

CH3CH2-O-SO3H +H2O and what does it make

Answer 14

Hydrolysis

To make CH3CH2OH

Question 15

CH3CH=CH2

To make CH3CH(OH)CH3

Answer 15

1) conc H2SO4
Electrophilic addition
2) H2O
Hydrolysis

Question 16

CH3CH=CH2 to CH3CH(Br)CH3

Answer 16

HBr room temp electrophilic addition

Question 17

Haloalkane to CH3CH2CN +KBr

Answer 17

KCN , ethanol

Nucleophilic substitution

Question 18

Haloalkane to CH3CH2OH +NaBr

Answer 18

NaOH/KOH
Warm/aq
Nucleophilic substitution

Question 19

Haloalkane to CH3CH2NH2

Answer 19

Ammonia
Ethanol/high p
Nucleophilic substitution

Question 20

Haloalkane to CH2=CH2

Answer 20

KOH ethanol

Elimination

Question 21

Nitrile to CH3CH2CH2NH2

Answer 21

LiAlH4
Ethoxyethane
Reduction

Question 22

Primary alcohol to Aldehyde

Answer 22

K2Cr2O7 / H+ distill off

Oxidation

Question 23

Primary alcohol to alkene

Answer 23

Conc H2SO4 180C

Dehydration/elimination

Question 24

Primary alcohol to R-COO- CH2CH3

Answer 24

R-COCl

Nucleophilic addition elimination

Question 25

Primary alcohol to CH3COOCH2CH3 + H2O

Answer 25

Ethanoic acid Conc H2SO4 Esterification

Question 26

Secondary alcohol to CH3CHOCH3 (ketones)

Answer 26

K2CR2O7/H+ | Oxidation

Question 27

Secondary alcohol to CH3CH=CH2

Answer 27

Conc H2SO4 180 Dehydration

Question 28

Carboxylic acid to CH3COONa +CO2+H2O

Answer 28

NaHCO3 room temp | Acid base

Question 29

Carboxylic acid to CH3COOR +H2O

Answer 29

ROH conc H2SO4 | Esterification

Question 30

CH3COOR to CH3COONa + ROH

Answer 30

NaOH reflux | Hydrolysis

Question 31

Aldehydes to CH3CH(OH)CN

Answer 31

KCN Add HCl in situ Nucleophilic addition

Question 32

``` CH3CH(OH)CN To CH3CH(OH)CH2NH2 ```

Answer 32

LiAlH4 Ethoxyethane Reduction

Question 33

Aldehyde to CH3COOH

Answer 33

Fehlings solution Heat Oxidation

Question 34

Aldehyde to CH3CH2OH

Answer 34

``` NaBH4 aq,warm Reduction Or H2/Ni 150 Reduction ```

Question 35

Ketone to (CH3)2C(OH)CN

Answer 35

HCN from KCN and HCl | Nucleophilic addition

Question 36

Ketone added fehlings solution

Answer 36

No reaction

Question 37

Ketone to CH3CH(OH)CH3

Answer 37

``` NaBH4 Nucleophilic addition Or H2/Ni 150 Reduction ```

Question 38

C6H6 to C6H6NO2

Answer 38

Conc HNO3 and conc H2SO4 | Nitration

Question 39

C6H6 to C6H12

Answer 39

H2/Ni 150 Reduction

Question 40

C6H6 to C6H5COCH3 +HCl

Answer 40

CH3COCl /ALCl3 | Electrophilic substitution

Question 41

Amino acid — H3N+CH2COOH

Answer 41

HCl | Acid base

Question 42

Amino acid to H2NCH2COO-

Answer 42

NaOH | Acid base

Question 43

Amino acid to H2nCH2COOCH3 +H2O

Answer 43

CH3OH Conc H2SO4 Esterification

Question 44

Amino acid to CH3CONHCH2COOH

Answer 44

CH3COCl room temp | Acylation

Question 45

Amino to H2NCH2COHNCH2COOH

Answer 45

Amino acid | Condensation

Question 46

Test | Bromine water

Answer 46

Add Br 2 Tests for C=C Orange to colourless positive

Question 47

Acidified K2CR2O7 test

Answer 47

``` Heat K2Cr2O7/H+ Test for Primary, secondary alcohol Aldehydes Go orange to green ```

Question 48

Tollens reagent test

Answer 48

Warm AgNO3 NaOH and NH3 Aldehydes Silver mirror

Question 49

Fehlings solution test

Answer 49

Fehlings A and B boil Blue to brick red Tests for aldehydes

Question 50

Hydrolysis followed by acidified AgNO3 year

Answer 50

``` NaOH heat then add AgNO3 Tests for haloalkane Cl - white Br- cream I - yellow ```

Question 51

Hydrolysis test

Answer 51

Add H20 Test for acyl chloride Steamy misty fumes