Ch 8 Alkenes: Structure and prepartion via Elimination reaction

Question 1

cis

Answer 1

same side

Question 2

trans

Answer 2

opposite sides

Question 3

Z

Answer 3

same side

Question 4

E

Answer 4

opposite side

Question 5

E2 Mechanism

Question 6

E2 rate of reactivity

Answer 6

3>2>1

Question 7

regioselectivity of E2 reactions

Answer 7

the reaction is said to produce two different regiochemical outcomes.both products are formed , but the more substituted alkene is generally observed to be the major product

Question 8

zaitsev product

Answer 8

the more substituted alkene

Question 9

hofmann product

Answer 9

the less substituted alkene

Question 10

when ethoxide is used the ______ product is the major product

Answer 10

Zaitsev

Question 11

When sterically hindered bases are used, the _______ product is the major product

Answer 11

hofmann

Question 12

potassium tert-butoxide (t-BuOK)

Answer 12

Question 13

Diisopropylamine

Answer 13

Question 14

triethylamine

Answer 14

Question 15

E1 mechanism

Question 17

b/c of their pair of e-,nu- can behave as ____

Answer 17

bases,recting with acidic protons of the alkyl substrate

elination reactions compete with nu- substitution reactions

Question 18

elimination reactions. draw it

Answer 18

the proton is removd from the alkyl substrate as it becomes bound to the base, and the departure of both the proton ant the electronegative leaing group yileds an alkene

Question 19

why are substitution and elimation reactions both possible

Answer 19

ever Nu- has some basic charater and every base has nucleo

Question 20

example of poor Nu-

Answer 20

water, HOR

Question 21

strong base with primary alkyl halide

Answer 21

SN2 is favored, E2 with strong non nucleophilic bases

Question 22

strong base secondary alkyl halide

Answer 22

mostly E2

Question 23

strong base with tiratry alkyl halide

Answer 23

E2

Question 24

weak base with primary alkyl halide

Answer 24

Sn2

Question 25

weak base with secoundary alkyl halide

Answer 25

mostly Sn2

Question 26

weak base and titary alkyl halide

Answer 26

Sn2/E1 in polar,protic solvents

Question 27

poor Nu- and alkyl halide

Answer 27

no reaction

Question 28

poor Nu- secondary alkyl halide

Answer 28

Sn1/ E1 (slowly) in polar protic solvent

Question 29

poor Nu- and tirtary alkyl halide

Answer 29

sn1/e1 in polar, protic solvents

Question 30

biomolecular reactions are faster on\_\_\_ carbon atoms and unimolecular reaction are _____ on tertiary barbom atoms

Answer 30

primary, faster

Question 31

hinderded bases favor ___ products even from primary carbon atoms

Answer 31

elimination

Question 32

alkoxides (R-O^-) are __ bases

Answer 32

strong

Question 33

good leaving groups are \_\_\_\_\_\_

Answer 33

weak bases( stable molecules)

Question 34

protonation of a poor leaving group ,make it a

Answer 34

a better leaving group and turns it into a weak base

Question 35

CH₃OK is

Answer 35

a strong basic Nu- methoxide