Organic Chemistry Ii Midterm 3

Front 1

base peak

Back 1

the highest peak in the mass spectrum

where the ion has been cleaved at the benzylic carbon

Front 2

sodium acetylide reactions with carbonyls

Back 2

forms new carbon carbon bond

Front 3

Grignard reaction products

Back 3

he Grignard Reaction is the addition of an organomagnesium halide (Grignard reagent) to a ketone or aldehyde, to form a tertiary or secondary alcohol, respectively. The reaction with formaldehyde leads to a primary alcohol.

Front 4

Grignard Reaction with Nitriles

Back 4

Front 5

Grignard Reactions with CO2

Back 5

Front 6

Grignard reactions with oxiranes

Back 6

Front 7

Smith Simmons Reagent

Back 7

Reactions with alkenes to give cyclopropanes

stereochemistry is conserved

Front 8

Preperation of iodomethylzinc

Back 8

CH2I2 + Zn in diethyl ether with copper=ICH2ZnI

Front 9

Which way is R?

Back 9

Clockwise

Front 10

Which way is S?

Back 10

Counterclockwise

Front 11

Olefin metathesis

Back 11

redistribution of alkene fragmenets

Front 12

Applications of olefin metathesis

Back 12

ring opening metathesis

ring closing metathesis

cross metathesis

Front 13

Grubbs catalyst

Back 13

used in olefin metatheisis

Front 14

RX + ZN(in diethyl ether)-RZnX

Back 14

Organozinc reactions

Front 15

What is iodomethylzinc used for?

Back 15

react w alekens to give cyclopropanes

takes double bond, splits and adds new bond to form triangle

Front 16

MgI

Back 16

Grignard reagent

Front 17

MgBr

Back 17

Grignard reagent

Front 18

Why are organometallic compounds useful?

Back 18

Because they have carbanionic character which makes them a source of nucleophilic carbons

Front 19

Reactivity of Grignard Reagents

Back 19

MgI>MgBr>MgCl

Front 20

lithium divinyl cuprate

Back 20

Front 21

Gilman reagents

Back 21

copper halide with 2 equivalents of alkyl or aryllithium

only one of the alk compounds stays on product

Front 22

benzyl group

Back 22

Front 23

amine

Back 23

Front 24

Organolithium/Magnesium reaction

Back 24

Front 25

Reactivity of types of halides

Back 25

alkyl>aryl>vinyl

Front 26

What affect do double and triple bonds have on polarity?

Back 26

increase polarity

Front 27

What are the three pieces of information obtained from an H NMR

Back 27

1. Location tells environment of carbon

2. Area(intergration) tells ratio of hydrogens

3. Shape indicates number of neighboring protons.

Front 28

When will two hydrogens on the same carbon not be equivalent?

Back 28

When there is a stereocenter!

Front 29

When will a methyl group have unequivalent hydrogens?

Back 29

NEVER!

Front 30

What is the larger number area in an NMR called??

Back 30

Downfield

Front 31

Alkane chemical shift

Back 31

1-2ppm

Front 32

What is the inductive effect?

Back 32

Withdrawl of electron density from one atom towards another, produces deshielded atoms

Front 33

When several halogens are present what happens to deshielding?

Back 33

Additive effect, more halogens=more deshielding

Front 34

methyl chemical shift

Back 34

0.9ppm

Front 35

methylene chemical shift

Back 35

1.2ppm

Front 36

methine chemical shift

Back 36

1.7ppm

Front 37

alcohol or ether effect on alpha proton shift

Back 37

+2.5

Front 38

oxygen of ester on alpha proton shift

Back 38

+3

Front 39

carbonyl group on alpha proton shift

Back 39

+1

Front 40

Why are aromatic hydrogens shift so strong?

Back 40

the net magnetic field of the aromaticity is very strong

Front 41

What causes multiplicity?

Back 41

The magnetic effect of neighboring hydrogens

Front 42

N+1 rule

Back 42

Neighboring carbons are n and 1 and that will give you the multiplicity of the given hydrogen

Front 43

coupling constant

Back 43

stronger the closer the chemical shifts are together

(J) the distance between the individual peaks

Front 44

Steps to analyzing proton nmr

Back 44

1. Degree of unsaturation

2. number and intergration of signal

3. analyze signals and draw fragments

4. assemble fragments

Front 45

What is the important aspect of C13 NMR?

Back 45

Chemical shift

Front 46

enantiotopic hydrogens

Back 46

end up with enantiomers when doing z substitution(with stereocenter present adjacent)

not equivalent but chemical shift is the same

Front 47

diastereotopic hydrogens

Back 47

different chemical shifts, not equivalent

diastereomers when z substitution

Front 48

can carbons be enatiotopic and diastereotopic?

Back 48

Yes

Front 49

Preparation of acetlyenic orgnolithium reagents

Back 49

terminal alkyne with alkyllithium

Front 50

Palladiun Cross Coupling

Back 50

mostly involves synthesizing biaryls

electronegative positive atoms removed and new carbon carbon bonds formed

Pd(0) reagent

Front 51

replace alcohol with halide

Back 51

add strong acid

Front 52

hydroboration

Back 52

breaks double bond adds OH anti M's rule syn addition

god for regio/stereoselective reactions

Front 53

oxidizing agent

Back 53

accepts electron from another species

Front 54

reducing agent

Back 54

donates electron to another species

Front 55

oxidation of primary alcohols and secondary alochol reagents

Back 55

PCC, C5H5NH, ClCrO3-, PDC Cr2O7

replaces alcohol with aldehyde for primary

replaces alcohol with ketone for seconday

Front 56

epoxide with grignard reagent

Back 56

creates primary alcohol

have two more carbons in product then grignard reagent

Front 57

Why can you not use a protic solvent in a grignard reaction?

Back 57

It destroys the reagent

Front 58

What does a ketone + Grignard reagent yield?

Back 58

Tertiary alcohol

Front 59

What does an aldehyde with a grignard reagent yield

Back 59

secondary alcohol

Front 60

What does formaldehyde with grignard reagent produce?

Back 60

primary alcohol

Front 61

Acid catalyzed reaction of alkenes + H2O

Back 61

water adds to double bond M's rule

Front 62

hydroboration-oxidation of alkenes

Back 62

no rearrangement H and OH add syn

opposite M's rule

Front 63

hydrolysis of alkyl halide

Back 63

Front 64

reduction of aldehydes by hydrogenation

Back 64

form primary alcohols

Front 65

reduction of ketones by hydrogenation

Back 65

forms secondary alcohols

Front 66

redution of ketone and aldehyde by metal hydride that can be used with protic solvents

Back 66

ketons still form secondary

aldehydes still form primary

doesnt require additional adding of water

Front 67

reduction of ketone and aldehyde by metal hydride with aprotic solvents

Back 67

must have water added as second step

due to volitality with water

Front 68

What is the reducing agent when using NaBH4

Back 68

BH4-

Front 69

Which reagents can you use to add an alcohol to an alkene with a carbonyl group?

Back 69

LiAlH4 or NaBH4 they will not reduce the alkene double bonds

Front 70

reduction of carboxylic acid

Back 70

ONly LiAlH4!

uses the same number of carbons in reactant and product

Front 71

general epoxide + grignard reagent mechanism

Back 71

Front 72

vicinal alcohol

Back 72

a compound with alcohols on adjacent carbons

Front 73

alkenes + osmiumtetraoxide

Back 73

stable but easily cleaed with tertbuytl alcohol

Front 74

dihydroxylation

Back 74

syn, vicinal addition of alcohols on double bond of alkene

-Reagents OsO4 with tert butyl alcohol in tert butyl alcohol

Front 75

products of dihydroxylation on alkenes

Back 75

if cis reagent 1 product

if trans 2 enatiomers(R and S)

Front 76

meso compounds

Back 76

a molecule with multiple stereocenters that is superimposable on its mirror image

Front 77

alcohol + hydrogen halide

Back 77

yields alkyl halide

Front 78

alcohol and thionyl chloride

Back 78

produces alkyl chlorides

Front 79

alcohol and phosphorous tribromide

Back 79

produces alkyl bromide

Front 80

acid catalyed dehydration of alcohol

Back 80

produces alkene

OH group removed and forms water

alkene formed where hydroxyl group was

Front 81

alcohol conversion to p=toulenesulfonates

Back 81

kicks off hydrogen adds R and SO2 group

Front 82

conversion of alchol to ether

Back 82

2 equivalents of the alchol + acid yeild RCH2 group on both sides of original oxygen

primary alcohols only

Front 83

REACTION:

Diol + H2SO4

Back 83

will form water and 5 or 6 member either when it can

primary, secondary, tertiary

Front 84

fischer esterification

Back 84

reversible, equilibrium lies slightly toward products

Front 85

Method to shift equilibrium of fischer esterification

Back 85

remove water

add more reactants

Front 86

Reaction to form ester(anhydride

Back 86

acid annhydride and alcohols in weak base(pyridine)

Front 87

reaction to form ester(protic)

Back 87

acyl chloride and alcohol

Front 88

oxidation of primary alcohol

Back 88

will form carboyxlic acid if in excess

Front 89

Which reagents can be used to synthesize aldehydes by oxidation

Back 89

pyridium chlorochromate PCC

pyridium dichlorochromate PDC with CH2Cl2

both stop at aldehyde before going to carboxylic acid

Front 90

alcohol oxidation to ketone

Back 90

secondary alcohol + PCD or PCC in CH2Cl2

Front 91

how would you know you havent formed a secondary or primary alcohol in an oxidation involving chromium?

Back 91

No color change

if it changes to green then most likely you have formed secondary or tertiary

Front 92

tertiary alcohol oxidation

Back 92

no reaction

Front 93

why avoid oxidation with chromium

Back 93

extremely toxic

Front 94

what nontoxic reagent can be used in oxidation of alcohols?

Back 94

chloro dimethylsulfonium

Front 95

formation of chloro dimethylsulfonium ion

Back 95

Front 96

swern oxidation mechanism

Back 96

Front 97

swern oxidationreactants and products

Back 97

primary alcohol produces aldehyde

secondary alcohol produces ketone

reagenet is DMSO+ NEt3

Front 98

REACTION:

Oxidative cleavage of 1,2 diols

Back 98

uses iodic acid NaIO4 or HIO4 to cleave the molecule in two

Front 99

REACTION:

Cyclic diol cleavage

Back 99

cleaves ring and add carbonyl groups where OH groups were with carbonyls on opposite ends

Front 100

thiol group structure and behavior

Back 100

R-SH

called cercapto group

larger

better nucleophle

no hyrogen bonding due to decreased polarity

Front 101

thiol preperation

Back 101

SN1

Front 102

production of disulfides

Back 102

Front 103

add alkane group in leaving groups position

Back 103

gilman reagent

Dialkyl copper lithium1

Front 104

where must the double bond be when identifying the area of hydrogenation?

Back 104

Where the chirality center is

Front 105

molecular formula rule of olefin cross metathesis

Back 105

original reactants - C2H4

Front 106

synthesis of primary alcohol using grignard reagents

Back 106

1. ethylene oxide

2. formaldehyde

Front 107

why cant tertiary alcohols be oxidized?

Back 107

No hydrogen on the carbon that the hydroxyl group is attached to to be removed

Front 108

List 7 Reactions to synthesize alcohols

Back 108

1. Reaction of alcohols with hydrogen halides
2. Reaction of alcohols with thionyl chloride
3. Reaction of alcohols and phosphorus tribromide
4. Acid catalyzed dehydration of alcohols
5. Conversion of alcohols to mesylates, tosylates, and triflates
6. Converting primary alcohols to ethers. (Condensation reaction)
7. Fischer Esterification

Front 109

PROPERTIES OF:

Reaction of alcohols with hydrogen halides and there reactivity

Back 109

Reactivity: 3* > 2* > 1*
Sn1

Front 110

PROPERTIES OF:

Reaction of alcohols with thionyl chloride

Back 110

1* and 2* alcohols
Sn2

Stereochemistry inverted

Produces alkyl chloride

Front 111

PROPERTIES OF:

Reaction of alcohols and phosphorus tribromide

Back 111

1* and 2* alcohols
Sn2

Front 112

PROPERTIES OF:

Acid catalyzed dehydration of alcohols

Back 112

E1
3* > 2* > 1*
rearrangement possible

Front 113

Why do we convert alcohols to mesylates, tosylates, and triflates

Back 113

makes OH a good leaving group

Front 114

PROPERTIES OF:

Converting primary alcohols to ethers. (Condensation reaction)

Back 114

2 Eq.
Protonation and Substitution pathway

Front 115

PROPERTIES/REAGENTS OF:

Fischer Esterification

Back 115

– Reversible reaction

Reagents:
1. Always 1 alcohol & 1 carboxylic acid
2. Acid (H2SO4)

Front 116

PROPERTIES/PRODUCTS OF:

Reaction of alcohols and acyl chlorides

Back 116

Removal of proton from alcohol, removal of Cl ion from acyl chloride

Products:
1. Ester formation
2. HCl formation

Front 117

PROPERTIES/PRODUCTS OF:

Reaction of alcohols and acid anhydrides

Back 117

Anhydride is cleaved at middle oxygen, acylate part is protonated, other part gets the R–O portion of alcohol

Products:
1. ester formation
2. carboxylic acid also formed

Front 118

REAGENTS FOR:

Oxidation of primary alcohols to carboxylic acids

Back 118

K2Cr2O7/K2CrO4/KMnO4

Front 119

REAGENTS FOR:

Oxidation of secondary alcohols to ketones

Back 119

PDC/PCC
in CH2I2
or

K2Cr2O7/K2CrO4/KMnO4

Front 120

REAGENTS FOR :

Oxidation of primary alcohols to aldehydes

Back 120

PDC/PCC in CH2I2

Front 121

REAGENTS FOR:

Oxidation and Cleavage of Vicinal Diols

Back 121

Periodic Acid (HIO4)

Front 122

PROPERTIES/PRODUCTS OF:

Oxidation and Cleavage of Vicinal Diols

Back 122

Vicinal Diols Only
Can be used to open cyclic diols
Cleavage between two OH bearing carbons
Carbonyl is formed on each carbon bearing the OH

Product: Ketone or Aldehyde, depending on substituents

Front 123

REAGENTS FOR:

Condensation reaction

Back 123

H2SO4

2 equivalents of primary alcohol as substrate

Produces ROR

Front 124

Describe an Acid Anhydride

Back 124

An organic compound with 2 acyl groups bound to the same oxygen.

(RCO)2––O

Front 125

REACTION:

Addition of primary alcohol with two additional carbons

Back 125

epoxide, H3O+

Front 126

REACTION:

Preparation of Diols

Back 126

Reduction of existing ketones or aldehydes with H2 and catalyst

Front 127

REACTION:

Preperation of Vicinal Diols

Back 127

Alkene + OsO4, Tertbutyl alcohol

Adds alcohols to both carbons of double bond

Front 128

REAGENT:

Add Chlorine

Back 128

SOCl2

Front 129

REAGENT:

Add Chlorine or Bromine to benzene

Back 129

FeCl3, Cl2

FeBr3, Br2

Front 130

Why use PDC/PCC instead of NaCr2O7

Back 130

-PCC/PDC will stop at ketone or aldehyde but Na2Cr2O7 will reduce all the way to carboxyli acid

Front 131

REACTION:

Cleavage of alkene by oxidizing reagent

Back 131

MnO4 in H3O or O3 in Zn

Aldehydes will be oxidized all the way to carboxylic acids

Front 132

REACTION:

Sodium Amide + Alcohol

Back 132

NaNH2 + ROH

Oxygen grabs Na

NaOR formed + NH3

Front 133

Fischer esterification reagent that adds a methyl group

Back 133

CH3OH in H2SO4