alkene mechanisms

Question 1

markovinkov’s rule

Answer 1

the H+ ion will go to the less substituted carbon (making the more stable carbocation)

Question 2

anti-markovinkov’s rule

Answer 2

the H+ ion will go to the more substituted carbon
- only works with HBr in presence of peroxide (ROOR)

Question 3

what rule do HCl and HI follow?

Answer 3

Markovinkov’s Rule

Question 4

What does HBr need to follow anti-markovinkov’s rule?

Answer 4

peroxide (ROOR)

Question 5

Addition of Water

Answer 5

• adding H2O
• forms an alcohol

Question 6

what rule does addition of water follow?

Answer 6

Markovinikov’s Rule

Question 7

common reagents of addition of water

Answer 7

H2SO4/H20
H3PO4/H20
H3O+

Question 8

Hydration by Oxymercuration-Demurcuration

Answer 8

no carbocation and no rearrangements formed

Question 9

what rule does hydration by oxymercuration-demercuration follow?

Answer 9

Markovinikov’s Rule

Question 10

common reagents of hydration by oxymercuration-demurcuration

Answer 10

Hg(OAc)2,H2O/NaBH4

Question 11

Alkomercuration-Demercuration

Answer 11

no carbocation and no rearrangements

Question 12

what rule does alkomercuration-demercuration follow?

Answer 12

Markovinkov’s Rule

Question 13

common reagents of alkomercuration-demercuration

Answer 13

Hg(OAc)2, OH-/NaBH4

Question 14

hydroboration

Answer 14

addition of borane

Question 15

what rule does hydroboration follow?

Answer 15

anti-markovinikov

Question 16

common reagents of hydroboration

Answer 16

BH3

Question 17

hydroboration-oxidation

Answer 17

syn addition

Question 18

common reagents of hydroboration-oxidation

Answer 18

BH3THF/H2O2, OH-
BH3THF/H2O2 NaOH-

Question 19

addition of halogens to alkenes

Answer 19

addition of Cl2,Br2,I2
no rearrangements
on adjacent carbons

Question 20

what addition is addition of halogens?

Answer 20

anti (trans)
- have to show stereochemistry and its enantimer

Question 21

halohydrin

Answer 21

alcohol with halogen on adjacent carbon
must have good nucleophile (H2O)

Question 22

what rule does halohydrin follow?

Answer 22

Markovinkov’s Rule

Question 23

what addition does halohydrin follow?

Answer 23

anti product (trans)

Question 24

what addition is catalytic hydrogenation?

Answer 24

syn addition (same side)

Question 25

common catalysts for catalytic hydrogenation

Answer 25

Pt, Pd, Ni, Wilkinson's Catalyst example: H2/Pt, H2/Pd

Question 26

addition of carbenes

Answer 26

adding CH2 to double bond which creates cyclopropane

Question 27

3 methods of adding carbenes

Answer 27

diazomethane, simmons-smith, and alpha elimation of haloform

Question 28

diazomethane

Answer 28

N2 + CH2

Question 29

simmons-smith reagent

Answer 29

CH2I2 + ZN ---> ICH2ZNI

Question 30

alpha elimination reagents

Answer 30

CHCl3/KOH,H2O haloform reacts with base

Question 31

epoxidation

Answer 31

alkene reacts with peroxyacid(OOH) to form epoxide (3 membered ring with 2 carbons and O)

Question 32

epoxidation reagent

Answer 32

perobenzoic acid (R-C(double bond O)-O-O-H)

Question 33

opening of epoxide ring

Answer 33

acid catalyzed - attacked by acid - then water attacks protanated epoxide and a transdiol is formed (one on dash, other on wedge)

Question 34

syn-hydroxylation

Answer 34

addition of two hydroxyl groups (one at each carbon of double bond)

Question 35

syn-hydroxylation reagents

Answer 35

OsO4/H2O2 KMnO4/OH ( permaganate has to be cold to form diols and hydrolysis with base)

Question 36

oxidative cleavage

Answer 36

pi and sigma bonds break C=C become C=O

Question 37

two methods of oxidative cleavage

Answer 37

1. warm/concentrated KMnO4 2. ozonolysis

Question 38

cleavage with MnO4

Answer 38

the disubstituted C forms Ketone the monosubstituted C forms carboxylic acid terminal = CH2 forms CO2

Question 39

ozonolysis

Answer 39

forms ketone and aldehydes

Question 40

oxynolysis reagents

Answer 40

O3/(Ch3)S

Question 41

syn addition

Answer 41

cis (same side)

Question 42

anti addition

Answer 42

trans (opposite sides) show stereochemistry and enantimer