Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Organic Chemistry > Organic Test 3 > Flashcards

Organic Test 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

Acid- Catalyzed Dehydration of an Alcohol Mechanism

A

By the E1 mechanism

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

What two different reagants can be used if you want to form an anti-diol from an alkene?

A
  1. MCPBA then H3O+
  2. CH3CO3 in water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Mechanism for Ionic Addition of HX to an alkene

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

Stability of Cis/Trans isomers

A

Trans isomers are generally more stable than the corresponding cis isomers.

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

oxymercuration-demercuration mechanism

A

**Results in a Markovnikov addition of OH and H without rearrangement. Use if you don’t want it to rearrange!

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

Free-Radical Halogenation of HBr

Result with peroxide

A

Results in an anti-markovnikov addition in the presence of peroxide

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

Platinum and H2 as reagants together do what ____

A

reduce alkene to alkane

(hydrogenation)

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

What is the mechanism for an Acid-Catalyzed opening of an Epoxide?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mechanism for Hydroboration of an alkene

A

**anti-mark

**syn-addition

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

Alkenes as Substituents

A

alkenyl groups:

methylene

vinyl

allyl

phenyl

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

What two reagants are used for oxidative cleavage of alkenes and what is the difference between them?

A
  1. KMnO4 (warm/conc.)

harsh, can’t recover aldehydes they are further oxidized into alcohols.

  1. O3

then (CH3)2S

can recover aldehydes

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

Addition of Hydrogen Halides to Alkenes

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

An E2 elimination takes place on a chair confirmation only if the proton and leaving group are _____

A

transdiaxial

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

E-Z nomenclature

A

If the two first-priority atoms are together (cis) on the same side of the double bond, you have the Z isomer, from the German word zusammen, “together.”

If the two first-priority atoms are on opposite (trans) sides of the double bond, you have the E isomer, from the German word entgegen, “opposite.”

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

Equation for Elements of Unsaturation

A

=(1/2)(2C+2-H)

C= Carbon

H= Hydrogen

Double bond= 1 element of unsaturation

A ring= 1 element of unsaturation

A triple bond= 2 elements of unsaturation

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

Zaitsev’s rule (stability of double bonds)

A

More substituted double bonds are usually more stable.

The alkyl groups attached to the double bonded carbons stabilize the alkene.

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

If an alkene can not easily undergo hydration in aqueous acid, what reagant can be used?

A
  1. Hg(OAc)2/ H2O
  2. NaBH4

(oxymercuration-demercuration)

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

Energy Differences in cis-trans isomers

A

Trans isomers are generally more stable than the corresponding cis isomers. In this case, the alkyl substituents are separated farther in trans isomers than they are in cis isomers.

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

Mechanism for the formation of Halohydrins (OH and X) from alkenes

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

What reagants are necessary to turn a double bond into a dibromocyclopropane?

A

CHBr3

KOH

and H2O

**cis/trans isomerism retained

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

Summary for naming Alkenes

A
  1. Select the longest chain or largest ring that contains the largest possible number ofdouble bonds, and name it with the -ene suffix.
  2. Number the chain from the end closest to the double bonds. Number a ring so that the double bond is between carbons 1 and 2. Place the numbers giving the locations of the double bonds in front of the root name (old system) or in front of the suffix -ene,
    - diene, etc. (new system).
  3. Name substituent groups as in alkanes. The ethenyl group and the propenyl group are usually called the vinyl group and the allyl group, respectively.
  4. Remember E-Z Nomenclature if you can’t use Cis/Trans. (Also, never forget R/ S if necessary)

(diene,triene,tetraene,etc)

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

What is a peroxide?

A
25
Q

What is the reagant necessary for catalytic hydrogenation (adding H2 across a double bond)?

What is the stereochemistry?

A

syn-addition

26
Q

What reagant can you use to form an acetylide ion?

A

NaNH2

27
Q

Dehydrohalogenation by the E2 mechanism

A

Reliable if poor SN2 substrate. One step.

28
Q

In aqueous conditions, what reagant can be used to create an epoxide?

A

peroxyacetic acid (CH3CO3H)

29
Q

When an epoxide is in a solution of ____ you end up with the anti-addition of 2 OH, a diol.

A

H3O+

epoxides are unstable in acid conditions

30
Q

Result of Branching on boiling point of Alkenes

A

increased branching lowers boiling point

31
Q
A
32
Q

Bredt’s Rule

A

** If there is a double bond at the bridgehead carbon of a bridged bicyclic system, one of the two rings contains a cis double bond and the other must contain a trans double bond.

**If the larger ring contains at least eight carbon atoms, than it can contain a trans double bond, and the bridgehead double bond is stable

33
Q

What reactants allow you to debrominate vicinal dibromides

A

NaI/ Acetone

By the E2 mechanism

34
Q

Stereochemistry of HBr, HCl, and HI when added to an alkene

A

forms an alkane that follows Markovnikov’s Rule.

Cation forms more stable intermediate (tertiary)

35
Q

What is formed in the simmons-smith reaction (CH2I2/ Zn(Cu))

A
36
Q

Reactant used to dehydrate alcohols into alkenes

A

conc. H2S04/ Heat

or H3PO4

37
Q

Mechanism of Debromination of Vicinal Dibromides

A
38
Q

Mechanism for the Formation of Carbenes

A
39
Q

Formation of a Hofmann product

A

-due to steric hindrance

40
Q

Stereochemsitry of Halogen Addition

A

**anti-addition.

41
Q

Acid-Catalyzed Hydration of an Alkene

A

**Follows markovnikov’s Rule

42
Q

What do you use if you want to add H and OH across a double bond in an anti-markovnikov and syn fashion?

A
  1. BH3THF
  2. H2O2/ -OH
43
Q

Hydration of an Alkene

A
44
Q

Numbering IUPAC rules

A

The chain is numbered starting from the end closest to the double bond, and the double bond is given the lower number of its two double-bonded carbon atoms

45
Q

Stereochemistry of the E2 reaction

A
46
Q

Alkoxymercuration- demercuration

A
47
Q

Order of reactivity of alcohol dehydrogenations

A

Go through the E1 mechanism

tertiary>secondary>> primary

Rearrangements are COMMON

48
Q

Anti-mark addition of H and Br to reduce alkene to alkane needs:

A

HBr and R-O-O-R (peroxide)

(**Doesn’t happen with HCl and HI)

49
Q

What two different reagants can be used if you want to form a syn-diol from an alkene

A
  1. OsO4/ H2O2

**expensive/highly toxic/volatile

  1. KMnO4/H20 (cold/dilute)

**cheap/ low yield/safer

***both are syn because the two Oxygens add at same time

50
Q

By what mechanism can an acetylide ion create larger organic molecules?

A

By an SN2 mechanism

Need a strong base/ good nucleophile

Primary and unhindered

**If hindered, the acetylide ion may abstract a proton, giving an E2 mechanism.

51
Q
A
52
Q

Mechanism for Free Radical Additon of HBr to Alkenes

A
53
Q

Addition of Halogens to Alkenes

A
54
Q

Treat an alkene with ____ to reduce to an alkane (hydrogenation)

A

platinum catalyst and H2

55
Q

Stability of Cycloalkenes

1) less than 5-membered
2) 5-membered or greater

A

1) less than 5-membered rings are unstable (ring strain)
2) 5-membered or greater rings are stable if cis. Trans rings must be 8-membered or larger to be stable.

56
Q

What reagant is used to turn an alkene into an epoxide? What is the configuration?

A

MCPBA

**retains stereochemistry

57
Q

Order of carbocation stability

A
58
Q

Markovnikov’s Rule

A
59
Q

What reagants are necessary to turn an alkene into a halohydrin (add an X and OH?)

A

X2 and H2O (aqueous)

**anti addition

**markovnikov

Organic Chemistry (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions