1. Reactions of Alkenes: Addition Reactions1

2. The characteristic reaction of alkenes is addition to the double bond.
Reactions of Alkenes
The characteristic reaction of alkenes is addition to the double bond. C A C B
+ A—B 2

3. Hydrogenation of Alkenes3

4. Hydrogenation of ethyleneC H H  C   
+ H—H
exothermic H° = –136 kJ/mol
catalyzed by finely divided Pt, Pd, Rh, Ni 4

5. Example
H3C
CH2
H2, Pt
H3C
CH3 H
(73%) 5

6. What three alkenes yield 2-methylbutane on catalytic hydrogenation?
Problem 6.1
What three alkenes yield 2-methylbutane on catalytic hydrogenation? 6

7. What three alkenes yield 2-methylbutane on catalytic hydrogenation?
Problem 6.1
What three alkenes yield 2-methylbutane on catalytic hydrogenation?
H2, Pt 6

8. Mechanism of catalytic hydrogenation. Figure 6.1B X Y H 8

9. Mechanism of catalytic hydrogenation. Figure 6.1B Y C C A X H H H H 9

10. Mechanism of catalytic hydrogenation. Figure 6.1B X Y H H H H 9

11. Mechanism of catalytic hydrogenation. Figure 6.1B Y A X H H H C C H 9

12. Mechanism of catalytic hydrogenation. Figure 6.1B X Y H H 9

13. Mechanism of catalytic hydrogenation. Figure 6.1B X Y H H 9

14. Heats of Hydrogenation
can be used to measure relative stability of isomeric alkenes
correlation with structure is same as when heats of combustion are measured 13

15. 126
119
115
CH3CH2CH2CH3 14

16. Heats of Hydrogenation (kJ/mol)
Ethylene 136
Monosubstituted
cis-Disubstituted
trans-Disubstituted
Terminally disubstituted
Trisubstituted 112
Tetrasubstituted 110 15

17. Problem 6.2
Match each alkene of Problem 6.1 with its correct heat of hydrogenation.
126 kJ/mol
118 kJ/mol
112 kJ/mol 16

18. Problem 6.2
Match each alkene of Problem 6.1 with its correct heat of hydrogenation.
highest heat of hydrogenation; least stable isomer
126 kJ/mol
118 kJ/mol
112 kJ/mol
lowest heat of hydrogenation; most stable isomer 16

19. Stereochemistry of Alkene Hydrogenation17

20. Two spatial (stereochemical) aspects of alkene hydrogenation:
syn addition of both H atoms to double bond
hydrogenation is stereoselective, corresponding to addition to less crowded face of double bond 18

21. syn-Addition versus anti-Addition18

22. Example of syn-AdditionH
CO2CH3
CO2CH3
H2, Pt
CO2CH3 H
(100%) 19

23. Stereoselectivity
A reaction in which a single starting material can give two or more stereoisomeric products but yields one of them in greater amounts than the other (or even to the exclusion of the other) is said to be stereoselective. 20

24. Example of stereoselective reaction
H3C
CH3 H
Example of stereoselective reaction
H2, cat
CH3
H3C H
CH3
H3C H
Both products correspond to syn addition of H2. 21

25. Example of stereoselective reaction
H3C
CH3 H
Example of stereoselective reaction
H2, cat
CH3
H3C H
But only this one is formed. 21

26. Example of stereoselective reaction
H3C
CH3 H
Example of stereoselective reaction
H2, cat
Top face of double bond blocked by this methyl group
CH3
H3C H 21

27. Example of stereoselective reaction
H3C
CH3 H
Example of stereoselective reaction
H2, cat
CH3
H3C H
H2 adds to bottom face of double bond. 21

28. Electrophilic Addition of Hydrogen Halides to Alkenes1

29. General equation for electrophilic addition – C E Y C
+ E—Y 2

30. When EY is a hydrogen halide – C H X C
+ H—X 2

31. Example CH3CH2 CH2CH3 HBr C CHCl3, -30°C H H CH3CH2CH2CHCH2CH3 Br
(76%) 4

32. Mechanism
Electrophilic addition of hydrogen halides to alkenes proceeds by rate-determining formation of a carbocation intermediate.
Electrons flow from the  system of the alkene (electron rich) toward the positively polarized proton of the hydrogen halide. 5

33. Mechanism + C C H .. : X – .. : H X C 6

34. Mechanism + C C H .. : X – .. : H X C H C .. X : 6

35. Regioselectivity of Hydrogen Halide Addition: Markovnikov's Rule7

36. Markovnikov's Rule
When an unsymmetrically substituted alkene reacts with a hydrogen halide, the hydrogen adds to the carbon that has the greater number of hydrogen substituents, and the halogen adds to the carbon that has the fewer hydrogen substituents. 8

37. Markovnikov's Rule HBr CH3CH2CH CH3CH2CHCH3 CH2 acetic acid Br (80%)
Example 1 9

38. Markovnikov's Rule CH3 H HBr C CH3 C acetic acid CH3 H Br (90%)
Example 2 10

39. Markovnikov's Rule
CH3 Cl
CH3
HCl
0°C
(100%)
Example 3 11

40. Mechanistic Basis for Markovnikov's Rule
Protonation of double bond occurs in direction that gives more stable of two possible carbocations. 12

41. Mechanistic Basis for Markovnikov's Rule: Example 1
acetic acid
HBr
CH2
CH3CH2CH Br
CH3CH2CHCH3 9

42. Mechanistic Basis for Markovnikov's Rule: Example 1
CH3CH2CH—CH Br – +
HBr
CH2
CH3CH2CH Br
CH3CH2CHCH3 9

43. Mechanistic Basis for Markovnikov's Rule: Example 1+
CH3CH2CH2—CH2
primary carbocation is less stable: not formed
CH3CH2CH—CH Br – +
HBr
CH2
CH3CH2CH Br
CH3CH2CHCH3 9

44. Mechanistic Basis for Markovnikov's Rule: Example 3Cl
CH3
0°C
HCl 14

45. Mechanistic Basis for Markovnikov's Rule: Example 3+
CH3
Cl –
HCl
CH3 H Cl
CH3
0°C
HCl 14

46. Mechanistic Basis for Markovnikov's Rule: Example 3
secondary carbocation is less stable: not formed H H H +
CH3 H +
CH3
Cl –
HCl
CH3 H Cl
CH3
0°C
HCl 14

47. Carbocation Rearrangements in Hydrogen Halide Addition to Alkenes15

48. Rearrangements sometimes occur
H2C
CHCH(CH3)2
HCl, 0°C H +
CH3CHCH(CH3)2 +
CH3CHC(CH3)2
CH3CHCH(CH3)2 Cl
CH3CH2C(CH3)2 Cl
(40%)
(60%) 16

49. Addition of Sulfuric Acid to Alkenes22

50. Isopropyl hydrogen sulfate
Addition of H2SO4
HOSO2OH
CH3CH
CH2
CH3CHCH3
OSO2OH
Isopropyl hydrogen sulfate
follows Markovnikov's rule:
yields an alkyl hydrogen sulfate 23

51. .. Mechanism .. CH3CH CH2 + H O SO2OH .. slow – + CH3CH CH3 .. + : O
fast
CH3CHCH3
OSO2OH : .. 24

52. Alkyl hydrogen sulfates undergo hydrolysis in hot water
CH3CHCH3 O
SO2OH +
H—OH
heat
CH3CHCH3 O H +
HO—SO2OH 25

53. Application: Coversion of alkenes to alcohols
1. H2SO4
2. H2O, heat
(75%) 26

54. H2C=CH2, RCH=CH2, and RCH=CHR' these don't:
But...
not all alkenes yield alkyl hydrogen sulfates on reaction with sulfuric acid
these do:
H2C=CH2, RCH=CH2, and RCH=CHR'
these don't:
R2C=CH2, R2C=CHR, and R2C=CR2
(These form polymers, sec 6.21) 27

55. Acid-Catalyzed Hydration of Alkenes19

56. Acid-Catalyzed Hydration of Alkenes+
H—OH
reaction is acid
catalyzed; typical
hydration medium is
50% H2SO4-50% H2O OH C H 2

57. Follows Markovnikov's RuleOH C
CH2CH3
CH3
H3C
CH3 H C
50% H2SO4
50% H2O
(90%) 3

58. Follows Markovnikov's Rule
CH3 OH
CH2
50% H2SO4
50% H2O
(80%) 4

59. involves a carbocation intermediate
Mechanism
involves a carbocation intermediate
is the reverse of acid-catalyzed dehydration of alcohols to alkenes OH C
CH3
H3C C
CH2 H+
+ H2O 5

60. Step (1) Protonation of double bond
Mechanism
Step (1) Protonation of double bond
H3C C
CH2 O + H : +
slow
H3C O H : + C
CH3 +
H3C H 6

61. Step (2) Capture of carbocation by water
Mechanism
Step (2) Capture of carbocation by water +
H3C C
CH3 H O :
fast + H O : C
CH3 6

62. Step (3) Deprotonation of oxonium ion
Mechanism
Step (3) Deprotonation of oxonium ion H O : C
CH3 O H : + +
fast H O : C
CH3 .. O + H : + 6

63. Acid-catalyzed hydration
Relative Rates
Acid-catalyzed hydration
ethylene CH2=CH2 1.0
propene CH3CH=CH2 1.6 x 106
2-methylpropene (CH3)2C=CH2 2.5 x 1011
The more stable the carbocation, the faster it is formed, and the faster the reaction rate. 9

64. Principle of microscopic reversibilityOH C
CH3
H3C C
CH2 H+
+ H2O
In an equilibrium process, the same intermediates and transition states are encountered in the forward direction and the reverse, but in the opposite order. 11

65. Thermodynamics of Addition-Elimination Equilibria19

66. Hydration-Dehydration Equilibrium
How do we control the position of the equilibrium and maximize the product? 13

67. Le Chatelier’s Principle
A system at equilibrium adjusts so to minimize any stress applies to it.
For the hydration-dehydration equilibria, the key stress is water.
Adding water pushes the equilibrium toward more product (alcohol).
Removing water pushes the equilibrium toward more reactant (alkene). 13

68. Hydroboration-Oxidation of Alkenes19

69. Suppose you wanted to prepare 1-decanol from 1-decene?
Synthesis
Suppose you wanted to prepare 1-decanol from 1-decene? OH 13

70. Suppose you wanted to prepare 1-decanol from 1-decene?
Synthesis
Suppose you wanted to prepare 1-decanol from 1-decene?
Needed: a method for hydration of alkenes with a regioselectivity opposite to Markovnikov's rule. OH 13

71. Synthesis
Two-step reaction sequence called hydroboration- oxidation converts alkenes to alcohols with a regiochemistry opposite to Markovnikov's rule.
1. hydroboration
2. oxidation OH 13

72. Hydroboration step C H BH2 C + H—BH2
Hydroboration can be viewed as the addition of borane (BH3) to the double bond. But BH3 is not the reagent actually used. 14

73. Hydroboration reagents:
Hydroboration step C H
BH2 C
+ H—BH2
Hydroboration reagents: H
Diborane (B2H6) normally used in an ether- like solvent called "diglyme"
H2B
BH2 H 14

74. Hydroboration reagents:
Hydroboration step C H
BH2 C
+ H—BH2
Hydroboration reagents:
Borane-tetrahydrofuran complex (H3B-THF) .. + O –
BH3 14

75. Oxidation step H2O2, HO– H BH2 C H OH C
Organoborane formed in the hydroboration step is oxidized with hydrogen peroxide. 17

76. Example
1. B2H6, diglyme
2. H2O2, HO– OH
(93%) 13

77. Example H C
CH3 OH
H3C
CH3
1. H3B-THF
2. H2O2, HO– C
H3C H
(98%) 13

78. Example OH
1. B2H6, diglyme
2. H2O2, HO–
(no rearrangement)
(82%) 13

79. Stereochemistry of Hydroboration-Oxidation19

80. Features of Hydroboration-Oxidation
hydration of alkenes
regioselectivity opposite to Markovnikov's rule
no rearrangement
stereospecific syn addition 18

81. only product is trans-2-methylcyclopentanol (86%) yield
syn-Addition
H and OH become attached to same face of double bond H
CH3 HO
CH3 H
1. B2H6
2. H2O2, NaOH
only product is trans-2-methylcyclopentanol (86%) yield 20

82. Mechanism of Hydroboration-Oxidation19

83. Hydroboration-oxidation
 electrons from alkene flow into 2P orbital of boron 22

84. Hydroboration-oxidation
H atom with 2 electrons migrates to C with
greatest (+) charge (most highly substituted). Syn add. 22

85. Hydroboration-oxidation
Anion of hydrogen peroxide attacks boron 22

86. Hydroboration-oxidation
Carbon with pair of electrons migrates to oxygen,
displacing hydroxide. Oxygen on same side as boron 22

87. Hydroboration-oxidation
Hydrolysis cleaves boron-oxygen bond resulting
in anti-Markovnikov addition 22

88. 1-Methylcyclopentene + BH3
syn addition of H and B to double bond
B adds to less substituted carbon 22

89. Organoborane intermediate23

90. Add hydrogen peroxide
OH replaces B on same side 23

91. trans-2-Methylcyclopentanol24

92. Addition of Halogens to Alkenes1

93. electrophilic addition to double bond forms a vicinal dihalide
+ X2 X X
electrophilic addition to double bond
forms a vicinal dihalide 2

94. Example
Br2
CH3CH
CH3CHCHCH(CH3)2
CHCH(CH3)2
CHCl3
0°C Br Br
(100%) 4

95. F2 addition proceeds with explosive violence
Scope
Limited to Cl2 and Br2
F2 addition proceeds with explosive violence
I2 addition is endothermic: vicinal diiodides dissociate to an alkene and I2 3

96. Stereochemistry of Halogen Addition
Anti-addition 5

97. trans-1,2-Dibromocyclopentane 80% yield; only product
Example Br H H
Br2 H Br
trans-1,2-Dibromocyclopentane 80% yield; only product 6

98. trans-1,2-Dichlorocyclooctane 73% yield; only product
Example H H
Cl2 Cl H Cl
trans-1,2-Dichlorocyclooctane 73% yield; only product 6

99. Mechanism of Halogen Addition to Alkenes: Halonium Ions7

100. Mechanism is electrophilic addition
Br2 is not polar, but it is polarizable
two steps involved (1) formation of bromonium ion (2) nucleophilic attack on bromonium ion by bromide 8

101. 2-methylpropene (CH3)2C=CH2 5400
Relative Rates
Bromination
ethylene H2C=CH2 1
propene CH3CH=CH2 61
2-methylpropene (CH3)2C=CH2 5400
2,3-dimethyl-2-butene (CH3)2C=C(CH3)2 920,000
More highly substituted double bonds react faster. Alkyl groups on the double bond make it more “electron rich.” 6

102. No obvious explanation for anti addition provided by this mechanism.
H2C +
CH2
Br2
BrCH2CH2Br ? + C Br : .. –
No obvious explanation for anti addition provided by this mechanism. 10

103. Cyclic bromonium ion Mechanism H2C + CH2 Br2 BrCH2CH2Br .. – + C C :10

104. Formation of bromonium ion
Mutual polarization of electron distributions of Br2 and alkene Br 11

105. Formation of bromonium ion–
Electrons flow from alkene toward Br2 Br Br + + 11

106. Formation of bromonium ion– Br
 electrons of alkene displace Br– from Br + Br 11

107. Stereochemistry – : Br .. + .. : Br ..
attack of Br– from side opposite C—Br bond of bromonium ion gives anti addition .. Br : .. 12

108. trans-1,2-Dibromocyclopentane 80% yield; only product
Example Br H H
Br2 H Br
trans-1,2-Dibromocyclopentane 80% yield; only product 6

109. Cyclopentene +Br2 15

110. Bromonium ion – 17

111. –
Bromide ion attacks the bromonium ion from side opposite carbon-bromine bond – 17

112. trans-Stereochemistry in vicinal dibromide19

113. Conversion of Alkenes to Vicinal Halohydrins20

114. alkenes react with X2 to form vicinal dihalides

115. alkenes react with X2 to form vicinal dihalides
alkenes react with X2 in water to give vicinal halohydrins C C
+ X2
+ H2O X OH
+ H—X 2

116. anti addition: only product
Examples
H2O +
H2C
CH2
Br2
BrCH2CH2OH
(70%) OH H H
Cl2
H2O H Cl
anti addition: only product 6

117. bromonium ion is intermediate
Mechanism .. O : Br .. + .. O +
bromonium ion is intermediate
water is nucleophile that attacks bromonium ion .. Br : .. 12

118. anti addition: only product
Examples
H2O +
H2C
CH2
Br2
BrCH2CH2OH
(70%) OH H H
Cl2
H2O H Cl
anti addition: only product 6

119. Cyclopentene + Cl2 26

120. Chloronium ion 28

121. Water attacks chloronium ion from side opposite carbon-chlorine bond29

122. trans-Stereochemistry in oxonium ion30

123. trans-2-Chlorocyclopentanol31

124. Regioselectivity
CH3 OH C
CH2Br
H3C C
CH2
Br2
H2O
(77%)
Markovnikov's rule applied to halohydrin formation: the halogen adds to the carbon having the greater number of hydrogens. 32

125. Explanation H O .. H O .. H3C H3C H3C H3C C CH2 CH2 C : Br : : Br : 
transition state for attack of water on bromonium ion has carbocation character; more stable transition state (left) has positive charge on more highly substituted carbon 34

126. Free-radical Addition of HBr to Alkenes
The "peroxide effect" 17

127. Markovnikov's Rule HBr CH3CH2CH CH3CH2CHCH3 CH2 acetic acid Br (80%)
Example 1 9

128. Addition of HBr to 1-Butene
CH2
CH3CH2CH
HBr Br
CH3CH2CHCH3
CH3CH2CH2CH2Br
only product when
peroxides added to reaction mixture
only product in absence of peroxides 18

129. Addition of HBr to 1-Butene
CH2
CH3CH2CH
HBr
addition opposite to Markovnikov's rule
occurs with HBr (not HCl or HI)
CH3CH2CH2CH2Br
only product when
peroxides added to reaction mixture 18

130. CH2
+ HBr h
CH2Br H
(60%)
Addition of HBr with a regiochemistry opposite to Markovnikov's rule can also occur when initiated with light with or without added peroxides. 19

131. Mechanism
Addition of HBr opposite to Markovnikov's rule proceeds by a free-radical chain mechanism.
Initiation steps: .. O R O . R .. .. O R . + 20

132. Mechanism
Addition of HBr opposite to Markovnikov's rule proceeds by a free-radical chain mechanism.
Initiation steps: .. O R O . R .. .. O R . + H .. : O . R .. .. . Br .. : + Br R O H + .. 20

133. . Br .. .. .. .. .. .. H Br .. . Br .. Propagation steps: : CH3CH2CH+ .
CH3CH2CH
CH2 Br : ..
Gives most stable free radical
CH3CH2CH
CH2 Br : .. ..
CH3CH2CH2CH2 Br : .. . .. + H Br : .. . Br .. : 21

134. Epoxidation of Alkenes1

135. are examples of heterocyclic compounds
Epoxides
are examples of heterocyclic compounds
three-membered rings that contain oxygen
ethylene oxide propylene oxide
H2C
CH2 O
H2C
CHCH3 O 2

136. Substitutive nomenclature: named as epoxy-substituted alkanes.
Epoxide Nomenclature
Substitutive nomenclature:
named as epoxy-substituted alkanes.
“epoxy” precedes name of alkane
1,2-epoxypropane 2-methyl-2,3-epoxybutane 1
CHCH3 O C
H3C 2 3 4
H2C
CHCH3 O 2

137. cis-2-Methyl-7,8-epoxyoctadecane
Problem Give the IUPAC name, including stereochemistry, for disparlure. O H
cis-2-Methyl-7,8-epoxyoctadecane 5

138. Epoxidation of Alkenes
RCOOH C +
peroxy acid O
RCOH C O + 6

139. Example
+ CH3COOH O
+ CH3COH O O
(52%) 7

140. Epoxidation of Alkenes
RCOOH C +
syn addition O
RCOH C O + 6

141. ethylene H2C=CH2 1 Relative Rates Epoxidation propene CH3CH=CH2 22
2-methylpropene (CH3)2C=CH2 484
2-methyl-2-butene (CH3)2C=CHCH3 6526
More highly substituted double bonds react faster. Alkyl groups on the double bond make it more “electron rich.” 6

142. Mechanism of Epoxidation6

143. Mechanism of Epoxidation6

144. Mechanism of Epoxidation6

145. Mechanism of Epoxidation6

146. Mechanism of Epoxidation6

147. Ozonolyis has both synthetic and analytical applications.
Ozonolysis of Alkenes
Ozonolyis has both synthetic and analytical applications.
synthesis of aldehydes and ketones
identification of substituents on the double bond of an alkene 15

148. Ozonolysis of Alkenes
First step is the reaction of the alkene with ozone. The product is an ozonide. C C O
+ O3 17

149. Ozonolysis of Alkenes
Second step is hydrolysis of the ozonide. Two aldehydes, two ketones, or an aldehyde and a ketone are formed. C C O
+ O3
H2O, Zn C O + C O 17

150. Ozonolysis of Alkenes
As an alternative to hydrolysis, the ozonide can be treated with dimethyl sulfide. C C O
+ O3
(CH3)2S C O C O + 17

151. Example CH3 CH2CH3 H C 1. O3 2. H2O, Zn CH2CH3 C O C O CH3 H + (57%)
(38%) 19

152. Introduction to Organic Chemical Synthesis1

153. Prepare cyclohexane from cyclohexanol
devise a synthetic plan
reason backward from the target molecule
always use reactions that you are sure will work 6

154. Prepare cyclohexane from cyclohexanol
ask yourself the key question
"Starting with anything, how can I make cyclohexane in a single step by a reaction I am sure will work?" 6

155. Prepare cyclohexane from cyclohexanolPt
The only reaction covered so far for preparing alkanes is catalytic hydrogenation of alkenes.
This leads to a new question. "Starting with anything, how can I prepare cyclohexene in a single step by a reaction I am sure will work?" 6

156. Prepare cyclohexane from cyclohexanol
H2SO4
heat H2 OH Pt
Alkenes can be prepared by dehydration of alcohols.
The synthesis is complete. 6

157. Prepare 1-bromo-2-methyl-2-propanol from tert-butyl alcohol
(CH3)3COH
(CH3)2CCH2Br OH
"Starting with anything, how can I make the desired compound in a single step by a reaction I am sure will work?"
The desired compound is a vicinal bromohydrin. How are vicinal bromohydrins prepared? 6

158. Prepare 1-bromo-2-methyl-2-propanol from tert-butyl alcohol
(CH3)2C
CH2
(CH3)2CCH2Br OH
H2O
Vicinal bromohydrins are prepared by treatment of alkenes with Br2 in water.
How is the necessary alkene prepared? 6

159. Prepare 1-bromo-2-methyl-2-propanol from tert-butyl alcohol
(CH3)3COH
H2SO4
heat
(CH3)2CCH2Br OH
Br2
H2O
(CH3)2C
CH2
2-Methylpropene is prepared from tert-butyl alcohol by acid-catalyzed dehydration.
The synthesis is complete. 6

160. Reactions of Alkenes with Alkenes: Polymerization1

161. Polymerization of alkenes
cationic polymerization
free-radical polymerization
coordination polymerization 2

162. Cationic Polymerization
Dimerization of 2-methylpropene
(CH3)2C
CH2
monomer (C4H8)
H2SO4
two dimers (C8H16)
CH3CCH
CH3
C(CH3)2
CH3CCH2C
CH3
CH2 + 3

163. Mechanism of Cationic Polymerization
CH3C
CH3 +
CH3
H2C C + H 3

164. Mechanism of Cationic Polymerization+
CH3
H2C C
CH3C
CH3CCH2C
CH3 + 3

165. Mechanism of Cationic Polymerization
CH3CCH
CH3
C(CH3)2
CH3CCH2C
CH3
CH2 +
CH3CCH2C
CH3 + 3

166. Free-Radical Polymerization of Ethylene
H2C
CH2
200 °C
2000 atm O2
peroxides
CH2
polyethylene 6

167. .. RO
Mechanism •
H2C
CH2 7

168. ..
RO:
Mechanism
H2C
CH2 • 9

169. ..
RO:
Mechanism
H2C
CH2 •
H2C
CH2 10

170. ..
RO:
Mechanism
H2C
CH2
H2C
CH2 • 10

171. ..
RO:
Mechanism
H2C
CH2
H2C
CH2 •
H2C
CH2 10

172. ..
RO:
Mechanism
H2C
CH2
H2C
CH2
H2C
CH2 • 10

173. ..
RO:
Mechanism
H2C
CH2
H2C
CH2
H2C
CH2 •
H2C
CH2 10

174. Free-Radical Polymerization of Propene
H2C
CHCH3 CH H
CH3
polypropylene 6

175. .. RO
Mechanism •
H2C
CHCH3 7

176. ..
RO:
Mechanism
H2C
CHCH3 • 9

177. ..
RO:
Mechanism
H2C
CHCH3 •
H2C
CHCH3 10

178. ..
RO:
Mechanism
H2C
CHCH3
H2C
CHCH3 • 10

179. ..
RO:
Mechanism
H2C
CHCH3
H2C
CHCH3 •
H2C
CHCH3 10

180. ..
RO:
Mechanism
H2C
CHCH3
H2C
CHCH3
H2C
CHCH3 • 10

181. ..
RO:
Mechanism
H2C
CHCH3
H2C
CHCH3
H2C
CHCH3 •
H2C
CHCH3 10

182. H2C=CHCl  polyvinyl chloride H2C=CHC6H5  polystyrene
F2C=CF2  Teflon 19