Download presentation
Presentation is loading. Please wait.
Published byAugusta Bishop Modified over 9 years ago
1
Alkenes Properties Nomenclature Stability 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
20
Establish Priority of Substituents on Each sp 2 Carbon
22
What’s My Name?
23
(Z)-4-ethyl-5-isopropyl-4-nonene
24
Priorities with Multiple Bonds
25
E or Z?
27
Name These
29
Hydrogenation Data Helps to Determine Stability H hydrogenation of Alkenes
30
Enthalpy Change Shows Relative Energy of Alkene
31
Both cis and trans 2-Butene are Hydrogenated to Butane
32
“E” is More Stable than “Z” by 2.3 KJ/mol
33
Relative Stabilities of Alkenes
36
Hyperconjugation bond associates with adjacent C-H bond
37
The Addition Reaction
38
HBr Addition
41
Markovnikov’s Rule The addition of H-X across a double bond results in the more highly substituted alkyl halide as the major product.
42
Depicting a Reaction
43
Addition of HBr or HCl Markovnikov Addition
44
Regiochemistry Determined by Stability of Intermediate
46
Hyperconjugation
47
Carbocation Stability more highly substituted, lower energy
49
3 o Carbocation forms Preferentially
53
What Alkenes are Needed to form Theses Alkyl Halides?
54
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.
55
Determine the major product:
57
Rearrangements
59
Propose a Mechanism
60
2 Possible pathways to the Carbocation Intermediates
61
Endo- transition state looks like product Exo- transition state looks like Reactant
62
Hammond’s Postulate Related species that are close in energy are close in structure. In an endothermic reaction, the transition state is similar to the product in structure and stability. In an exothermic reaction, the transition state is similar to the reactant in structure and stability. i.e. the structure of the transition state resembles the structure of the most stable species.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.