Chapter 17

Question 1

conjugated dienes

Answer 1

continuous system of overlapping pi bonds

Question 2

preparation of conjugated dienes

Answer 2

from allylic halides via elimination or dihalides via 2 elimination reactions

Question 3

preparation of conjugated dienes - reagants

Answer 3

bulky bases to prevent SN2 reactions

Question 4

stability - bonds

Answer 4

conjugated are more stable

Question 5

equilibrium conformation

Answer 5

trans conformation

Question 6

Electrophilic addition of dienes

Answer 6

addition of HX

produces 2 products 1,2 and 1,4 adducts

Question 7

Electrophilic addition - production of 2 products

Answer 7

first is produced normally, second is produced via resonance structure

Question 8

Bromination of diene

Answer 8

produces 1,2 and 1,4 adducts

addition of BR molecules

Question 9

Diels - Alder reactions

Answer 9

2 carbon bonds are formed simultaneously

favoured by moderate temps

Question 10

Diels - Alder reactions - high temps

Answer 10

disfavours products

achieves reverse diels alder reaction (breaks compound in 2)

Question 11

Dienophile - substituents

Answer 11

adding substituents causes reaction to occur more rapidly

Question 12

Diene - Diels alder reaction

Answer 12

must be cis configuration

if it can be in cis form wont react

Question 13

Endo

Answer 13

syn to the larger bridge
electron withdrawing substituents occupy endo
highly favoured

Question 14

Exo

Answer 14

anti to large bridge