Download presentation
Presentation is loading. Please wait.
Published byJeremy Stafford Modified over 9 years ago
1
Alkenes Properties Nomenclature Addition Reactions
2
Ethylene
3
Electron Rich -Bond
4
Cis and Trans no rotation about -bond
5
Elements or Degrees of Unsaturation: -Bond or Ring
6
Halogens replace Hydrogens
7
Saturated compounds with Oxygen and Nitrogen
9
Determine the # elements of Unsaturation
10
Alkene Nomenclature
12
Cyclic alkenes
13
Alkyl Groups with -Bonds
14
Alkylidene Groups Double Bonds Fused to Rings
15
Polyenes
16
Name these Alkenes
17
cis-trans Isomers
18
E/Z System
19
What’s My Name?
20
(Z)-4-ethyl-5-isopropyl-4-nonene
22
Establish Priority of Substituents on Each sp 2 Carbon
24
Priorities with Multiple Bonds
25
E or Z?
27
Name These
29
Preparation of Alkenes E2 - Elimination reactions of alkyl halides and tosylates (or mesylates) E1 - Acid catalyzed dehydration of alcohols
30
Hydrogenation Data Helps to Determine Stability H hydrogenation of Alkenes
31
Enthalpy Change Shows Relative Energy of Alkene
32
Both cis and trans 2-Butene are Hydrogenated to Butane
33
“E” is More Stable than “Z” by 2.3 KJ/mol
34
Relative Stabilities of Alkenes
36
Hyperconjugation bond associates with adjacent C-H bond
37
The Addition Reaction
38
HBr Addition
39
Markovnikov’s Rule The addition of H-X across a double bond results in the more highly substituted alkyl halide as the major product.
40
Addition of HBr or HCl Markovnikov Addition
41
Regiochemistry Determined by Stability of Intermediate
42
3 o Carbocation forms Preferentially
43
Carbocation Stability more highly substituted, lower energy
44
Asymmetric Center is Generated Racemic Mixture Formed
45
Definitions Regioisomers – two constitutional isomers that could result from an addition reaction. Regiospecific – only one regiosisomer forms at the expense of the other. Regioselective – both regioisomers are formed, but one is formed in preference.
46
Determine the major product:
48
Rearrangements
49
HBr Addition with RO-OR Anti-Markovnikov
50
Free-Radical Mechanism
51
Addition of Br 2
52
More Definitions Stereospecific – only one stereoisomer is formed at the expense of the other (e.g. trans vs. cis) Stereoselective – one stereoisomer is formed preferentially over the other.
53
Anti-Addition Stereospecific Reaction Anti-addition
54
Bromonium Ion Intermediate
55
Trans is formed exclusively No Meso is formed (cis)
56
Bromonium Ion is Opened Equally from Both Sides
57
Brominations Often Generate Asymmetric Centers
58
trans alkene + anti addition = MESO
59
Provide a Mechanism
60
Halohydrin Formation Addition of Br – OH Stereospecific & Regiospecific
61
Unsymmetrical Bromonium ion H 2 O opens ring at more hindered site
62
Br and OH are trans in anti addition
63
Catalytic Hydrogenation syn addition
64
Mechanism
65
Syn Addition of H 2
66
Reactions that Generate Chirality Centers Hydrogenation, syn
67
Hydrogenation all alkene bonds are reduced
68
Asymmetric Induction
69
Preparation of (L)-Dopa for Treatment of Parkinson’s
70
10 pt. problem 7.(10) Consider the compound 3(S),5,5- trimethylcyclohexene. Upon reduction with H 2 on a 1% Pt/C catalyst, the resulting product has an absolute configuration of (R). Draw the equation for this reaction, clearly drawing the starting alkene and the product alkane and explain why the absolute configuration is completely inverted in this reaction.
71
Hydration Addition of H 2 O
72
Oxymercuration Hydration Markovnikov addition Regiospecific Reaction
73
Oxymercuration Mechanism
74
Hydroboration Hydration Anti-Markovnikov Syn addition
75
Hydroboration
76
Draw the Major Products
77
2 Complementary Hydration Reactions
78
Cyclopropanation
79
Simmons-Smith Reaction
80
In situ Preparation of Carbene
81
Two MCAD Inhibitors
82
MCPA and SPA
84
Ozonolysis Alkene Cleavage
85
Mechanism of Ozonolysis
86
Addition polymers
87
Air Pollution Reacts with Tires
88
O 3 reacts with all alkene Bonds
89
Problem An unknown compound A, C 8 H 16, reacts with H 2 on a 1% Pt/C catalyst to form B (C 8 H 18 ). B has two chiral centers but is optically inactive due to the presence of an internal plane of symmetry. Treatment of A with O 3 followed by Zn/HOAc affords butanone only. Identify A and B and draw B in a Fischer projection.
91
What is the Structure of Limonene? Solomons 8.39
92
C=C bonds become carbonyl groups
93
Acid Catalyzed Dimerization Solomons 8.58
94
Hoffmann Product via E1
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.