Chapter 8

Question 1

Requirements of an elimination reaction

Answer 1

a strong base

Question 2

when are mixtures possible in elimination reactions?

Answer 2

when multiple beta-hydrogens are present

Question 3

Zaitsev’s Rule

Answer 3

major product of beta-elimination will the most stable alkene

Question 4

how many steps in E1

Answer 4

2 steps, a fast step and a slow step

Question 5

Amount of steps in E2

Answer 5

1, much like SN2

Question 6

what stereochemistry is favorable in E2 rxn

Answer 6

anti and coplanar (H and X in same plane)

Question 7

SN1 vs E1

Answer 7

• difficult to predict, need experiments to verify
• results in mixtures of each

Question 8

SN2 vs E2

Answer 8

• Good nucleophile increases ratio of SN2
• High basicity of Nucleophile increases ratio of E2

Question 9

naming an Alkene

Answer 9

Number the carbon chain and mark position where dbl bond starts

Question 10

Alkenyl group

Answer 10

same as alkyl groups for alkenes

Question 11

Possibilities of Cyclic acids

Answer 11

Double bonds may be in the ring or out of the ring

Question 12

Endocyclic Double bonds

Answer 12

Dbl bonds inside the ring

Question 13

Exocyclic Dbl Bonds

Answer 13

out of the ring

Question 14

when is methylene used in naming

Answer 14

when Dbl bond is exocyclic

Question 15

C2 to C4 alkenes are

Answer 15

gases at STP

Question 16

Highly substituted alkenes are

Answer 16

more stable

Question 17

Why are highly subbed alkenes more stable?

Answer 17

SP2 hybrid atoms attract electrons. since R groups are e- donators, then this donation stabilizes the SP2 C

Question 18

Cis/trans more stable?

Answer 18

trans isomers are more stable

Question 19

why are trans isomers more stable

Answer 19

the two substituents cause strain in the cis molecule

Question 20

Dehydrogenation

Answer 20

rxn that loses hydrogen gas (H2)

Question 21

Dehydration of alcohols causes

Answer 21

loss of H2O from an alcohol

Question 22

Which type of carbon is easiest to hydrate?

Answer 22

tertiary

Question 23

Zaitsev rule- applied to dehydration

Answer 23

elimination reactions of alcohols yield the most highly substituted alkene as the major product

Question 24

rates of reactivity for E1 and E2

Answer 24

• Primary are the slowest
• tertiary are the fastest

Question 25

E1 and E2 mechanisms for dehydration are promoted by

Answer 25

acids

Question 26

When is E1 favored in dehydration

Answer 26

when a tertiary alcohol is used

Question 27

T/F cations will rearrange to more stable states

Answer 27

True

Question 28

Dehydrohalogenation of Alkylahlides eliminate

Answer 28

HX

Question 29

Which halides are favored in E2

Answer 29

primary or secondary

Question 30

What type of base does E2 require?

Answer 30

strong base

Question 31

Elimination in Cyclohexane

Answer 31

eliminating HX must be anti and coplanar