orgo 2 > Exam 1 > Flashcards

Exam 1 Flashcards

(61 cards)

Study These Flashcards
1
Q

How can we generate ethers (which kinds of reactions)?

A

Williamson ether or acid catalyzed addition of an alcohol to an alkene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is required for Williamson Ether?

A

Primary alkyl halide, alkoxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How to determine thte best substrate for williamson ether?

A

Less substituted carbons should have alkyl halide, more substituted should be alkoxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the steps of williamson ether.

A

Deprotonation of alkoxide, SN2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is required for acid catalyzed adidition of an alcohol to an alkene?

A

Alcohol and acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Is acid cat addn markovnikov or anti markovnikov

A

Markovnikov

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the mechanism of acid catalyzed addition of alcohols

A

Pi bond breaking (deprotoate alcohol) and carbocation formation, nucleophilic attack by deprotonated alcohol, deprotonation of product

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How can epoxides be synthesized (rxns)

A

Oxidation of alkenes with peracids, or cyclization of halohydrins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the mechanism of alkene epoxidation

A

Alkene double bond adds to central O of peracid, same O gives electrons to C of alkene, peracid single bond jumps to carbonyl single bond, peracid double bond gives electrons to H

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the stereochemistry of alkene epoxidation?

A

Cis –> syn
Trans –> anti

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the steps of halohydrin epoxidation

A

Deprotonation of the halohydrin, intramolecular SN2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Stereochemical restraints of epoxidation via halohydrin cyclization

A

Step 2 of halohydrin cyclizatyion is SN2, which requires a backside attack (and inversion of stereochemistry). In order for this to happen, the OH and the halogen must be trans to one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the two ways that epoxide rings can be opened?

A

Under acid or basic conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the opening of epoxides under acidic conditions

A

Protonation by acid, SN2 on more substituted C (O as LG) to open ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the opening of epoxides under basic conditions

A

SN2 (base as nuc), protonation of alkoxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are organometallic reagents (define)

A

compounds containing carbon-metal bonds (e.g., Li, Mg, Cu) that act as strong nucleophiles and bases, crucial for forming new C-C bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Examples of Organometallic reagents

A

Grignard Reagents (R-MgX), organocuprates (R2CuLi)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How can organometallic reagents be used?

A

To open epoxide rings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the mechanism of orgamometallic reagents?

A

SN2, (attacking the less substituted carbon), then acidic workup (protonation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a diol

A

Organic compound with two OH groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a way to generate diols

A

Alkene dihydroxylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do we cleave diols

A

Oxidative cleavage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the solvents // reactants in alkene dihydroxylation?

A

OSO4 cat and NMO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the solvents // reactants in oxidative clevage of diols?

A

H5IO6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Describe the product of diols that undergo oxidative cleavage
2 compounds with carbonyls (in place of hydroxyls) produced
26
How do we cleave ethers
Using strong acids (HBr or HI)
27
Describe the mechanism of ether cleavage
Protonation of reactant (which deprotonates acid), then SN2 of more sub C
28
What are the various alkyne reactions?
Hydrohalogenation (HX addition), catalyzed hydration, hydroboration oxidation, catalytic hydrogenation, acid/base to alkyne
29
Describe the steps of hydrohalogenation of alkynes
Triple bond oxidation + H addition (generates carbocat), X (nuc) attacks more substituted carbon
30
What reagents/solvents are involved in catalyzed hydration of alkynes
Water, strong acid
31
Describe the steps of catalyzed hydration of alkynes
1) oxidation of triple bond and H addition (using acid, generates carbocation), rearrangement if needed, nuc attack of carbocation with water, deprotonation using water
32
What is keto-enol tautomerization
Rapid interconversion between ketone (carbonyl + R groups) and enol
33
Describe the mechanism of keto enol tautomerization to form a ketone
1) hydroxyl O donates electrons to make double bond, existing double bond oxidized + protonation with acid 2) nuc attack + deprot
34
What are the required reagents for hydroboration oxidation of alkynes
1) BHR2 2) H2O2, NaOH, H2O
35
How do we fully reduce alkynes to alkanes (name of rxn + reagents)
Full reduction via catalytic hydrogenation. 2 H2 + Pt/Pd/Ni
36
How do we partially reduce alyknes to cis alkenes (name of rxn + reagents)
Partial reduction via catalytic hydrogenation: H2 + Lindlars Catalyst
37
How do we partially reduce alkynes to trans alkenes (name of rxn + reagents)
Partial reduction via catalytic hydrogenation: Na/NH3
38
What is the mechanism of catalytic hydrogenation of an alkyne (to generate trans alkene)
Na has free radical, donates electron to triple bond, which donates pair of electrons to aadjacent carbon. Protonation by NH3. Free e- donated to free radical. Lone pair protonated by NH3
39
How can we deprotonate alkynes?
Using NaNH2
40
Mechanism of using NaNH2 to deprotonate alkynes
negatively charged N of NH2 attacks H of alkyne, which donates e- to adjacent carbon.
41
What is the role of diels alder
Concerted, stereospecific (4+2) cycloaddition that generates 2 new C-C bonds and a new pi bond (aka generates a cyclohexane using two alkenes)
42
Which two molecules react to generate a cyclohexane in diels alder
Diene (two pi bonds with a sigma bond between) and dienophile
43
Describe the mechanism of diels alder?
CONCERTED; clockwise/counterclockwise. dienophile pi bond attacks carbon of diene, adjacent pi bond on diene moves, next pi bond attacks carbon of dienophile
44
Which reaction is likely occurring if you see ROH as the reagent (and primary alkyl halide as reactant)?
Williamson ether
45
Reagent = H5IO6/HIO4 or OsO4 Which reaction?
Oxidative cleavage of diols
46
Reagent = 2 H2, Pt/Pd/Ni Which reaction?
Catalytic hydrogenation (full reduction)
47
Reagent = H2, Lindlars cat Which reaction?
Catalytic hydrogenation (to cis alkene)
48
Reagent = Na/NH3 Which reaction?
Catalytic hydrogenation (to trans alkene)
49
Reagent = 1) R2BH 2) NaOH, H2O2, H20 Which reaction?
Hydroboration oxidation
50
Reagent = ROH, acid Which reaction?
Acid catalyzed addition of alcohol to alkene
51
52
IR: 1600-1850
Double bonds. CC/CN/CO
53
IR: 2100-2300
triple bonds
54
2500-4000
bonds to H
55
IR: broad band 1700
C=O
56
IR: broad 3200-3600
OH
57
Is OH or NH peak broader
OH
58
IR: 2850-3100
CH
59
IR: 1700
Carbonyl
60
IR: 3300-3600
Hydroxyl
61
IR: near 3000
Hydrocarbons
orgo 2
flashcards
Decks in class (7)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions