Flashcards in Chapter 17 Deck (14):
1
conjugated dienes
continuous system of overlapping pi bonds
2
preparation of conjugated dienes
from allylic halides via elimination or dihalides via 2 elimination reactions
3
preparation of conjugated dienes - reagants
bulky bases to prevent SN2 reactions
4
stability - bonds
conjugated are more stable
5
equilibrium conformation
trans conformation
6
Electrophilic addition of dienes
addition of HX
produces 2 products 1,2 and 1,4 adducts
7
Electrophilic addition - production of 2 products
first is produced normally, second is produced via resonance structure
8
Bromination of diene
produces 1,2 and 1,4 adducts
addition of BR molecules
9
Diels - Alder reactions
2 carbon bonds are formed simultaneously
favoured by moderate temps
10
Diels - Alder reactions - high temps
disfavours products
achieves reverse diels alder reaction (breaks compound in 2)
11
Dienophile - substituents
adding substituents causes reaction to occur more rapidly
12
Diene - Diels alder reaction
must be cis configuration
if it can be in cis form wont react
13
Endo
syn to the larger bridge
electron withdrawing substituents occupy endo
highly favoured
14