1. SL Reaction pathways
Deduce reaction pathway given the starting materials and the product, e.g:
CH3CH2OH CH3CH2CHO
Conversions with more than two stages will not be assessed. Reagents, conditions and equations should be included
The compound and reaction types in this topic are summarized in the schemes on the next slides
K2Cr2O7

2. propane propanoic acid polypropene propanal 1-propanol propene
oxidation
polypropene
propanal
oxidation
(M) polyaddition
+H2O
1-propanol
addition
propene
(M) substitution
+OH-
addition
+HCl
addition
1-chloro-propane
+H2
(M) substitution via radical reaction
1,2-dichloro-propane
(M) substitution via radical reaction
propane
(M) further radical substitution to tri- and tetra-chloropropane

3. propane propanoic acid propanal polypropene 1-propanol propene
Oxidation of primary alcohol with acidified K2Cr2O7.
Reflux to get the product
propanal
polypropene
Oxidation of primary alcohol with acidified
K2Cr2O7. Distillation to get the product
Poly-addition. Radical mechanism.
Initiation, prolongation and termination
1-propanol
Addition reaction.
Hydrogen halide (HCl),
spontaneous at STP
(M) substitution reaction with NaOH;
SN1 or SN2
propene
1-chloro-propane
Addition reaction.
H2 and Ni-catalyst
(M) substitution via radical mechanism.
Induced by homolytic cleavage of Cl2
by UV-light
(M) substitution via radical mechanism.
Induced by homolytic cleavage of Cl2
by UV-light
1,2-dichloro-propane
propane
(M) further radical substitution to tri- and tetra-chloropropane

4. carboxylic acid polyalkene aldehyde primary alcohol alkene
oxidation
aldehyde
(M) polyaddition
oxidation
alkene
primary alcohol
(M) substitution
+OH-
addition
addition
+HCl
+Cl2
chloroalkane
(M) substitution via radical reaction
(M) substitution via radical reaction
dichloroalkane
alkane
(M) further radical substitution to tri- and tetra-chloropropane

5. butane 1-chloro-butane What is formed? oxidation oxidation
(M) polyaddition
addition
+HCl
(M) substitution
+OH-
addition
1-chloro-butane
+H2
(M) substitution via radical reaction
(M) substitution via radical reaction
butane
(M) further radical substitution to tri- and tetra-chloropropane

6. propane propanone polypropene 2-propanol 1-propene 2-chloro-propane
oxidation
(M) polyaddition
2-propanol
1-propene
addition
+HCl
(M) substitution
+OH-
addition
+H2
2-chloro-propane
1,2-dichloro-propane
(M) substitution via radical
reaction
(M) substitution via radical reaction
propane
(M) further radical substitution
to tri- and tetra- chloropropane

7. propane propanone polypropene 2-propanol 1-propene 2-chloro-propane
Oxidation of secondary alcohol with acidified K2Cr2O7
polypropene
2-propanol
(M) polyaddition
(M) substitution
+OH-
addition
1-propene
2-chloro-propane
+HCl
addition
(M) substitution via radical
reaction
+Cl2
(M) substitution via radical reaction
1,2-dichloro-propane
propane
(M) further radical substitution to tri- and tetra chloropropane

8. polyalkene ketone secondary alcohol alkene secondary chloroalkane
oxidation
(M) polyaddition
secondary
alcohol
addition
(M) substitution
+OH-
+HCl
alkene
addition
secondary
chloroalkane
+H2
(M) substitution via radical
reaction
(M) substitution via radical reaction
alkane
dichloroalkane
(M) further radical substitution to tri- and tetra chloropropane

9. butane 2-chloro-butane What is formed? oxidation substitution
+OH-
2-chloro-butane
substitution via radical
reaction
butane

10. Draw structural formula of reactants and products, name them and give reaction pathway
K2Cr2O7
CH3CH2CHO H2
CH3CH=CHCH3
NaOH
K2Cr2O7
CH3Br
UV-light, Cl2
CH3CH3 HI
CH3CH=CHCH2CH3

11. Answers K2Cr2O7 CH3CH2CHO CH3CH2COOH oxidation propanal propanoic acid
CH3CH=CHCH3
CH3CH2CH2CH3
addition
2-butene
butane
NaOH
K2Cr2O7
CH3Br
CH3OH
CH2O
substitution
oxidation
methylbromide
methanol
methanal
UV-light, Cl2
CH3CH3
CH2ClCH3
radical substitution
ethane
chloroethane HI
CH3CH=CHCH2CH3
CH3CHICH2CH2CH3
addition
2-pentene
2-iodopentane

13. 1-3. Substitution via radical mechanism
1-3. Substitution via radical mechanism. Induced by homolytic cleavage of Cl2 by UV-light.
4. Addition reaction. Hydrogen halide, spontaneous at STP
5. Addition reaction. H2 and Ni-catalyst
6. Addition reaction. Halogene, spontaneous at STP
7. Poly-addition. Radical mechanism. Initiation, prolongation and termination
8. Substitution reaction with NaOH; SN1 or SN2
9. Oxidation of primary alcohol with acidified K2Cr2O7. Distillation to get the product
10. Oxidation of primary alcohol with acidified K2Cr2O7. Reflux to get the product
11. Oxidation of secondary alcohol with acidified K2Cr2O7

14. HL Reaction pathways propene 1-chloro-propane butanenitrile 1-propanol
(M) Substitution reaction. SN1 or SN2
CN-
propene
1-chloro-propane
butanenitrile
(M) Elimination reaction.
Hot, concentrated and reflux
Reduction with H2
and Ni-catalyst
(M) Substitution reaction.
SN1 or SN2
NH3
1-propanol
propylamine, butylamine
Condensation reaction.
Acid catalyst (or alkaline catalyst,
but more common when hydrolysis of ester).
Equilibrium reaction.
Condensation reaction.
Acid catalyst (or alkaline
catalyst).
Equilibrium reaction.
propanoic acid
1-propyl propanoate
propyl amide

15. HL Reaction pathways nitrile alkene chloropropane alcohol amine
(M) Substitution CN-
(M) Elimination
chloropropane
Reduction
(M) Substitution
alcohol
amine
Condensation
carboxylic acid
Condensation
ester
amide

16. 1-chloro-butane 1-butanol butanoic acid What is formed?
substitution CN-
1-chloro-butane
elimination
reduction H2
substitution NH3
1-butanol
Condensation reaction.
Acid catalyst (or alkaline catalyst,
but more common when hydrolysis of ester).
Equilibrium reaction.
Condensation reaction.
Acid catalyst (or alkaline
catalyst).
Equilibrium reaction.
butanoic acid

17. HL Reaction pathways
alkene
1. Elimination reaction. Hot, concentrated and reflux
2. Substitution reaction. SN1 or SN2
3. Substitution reaction. SN1 or SN2. (Can be substituted up 4 times to a quarternary ammonum salt)
4. Condensation reaction. Acid catalyst (or alkaline catalyst, but more common when hydrolysis of ester). Equilibrium reaction.
5. Condensation reaction. Acid catalyst (or alkaline catalyst). Equilibrium reaction.
6. Nitrile to amin: Reduction with H2 and Ni-catalyst 6