O-Chem 2 review

Miscellaneous

Aromatics

EAS Reactions

Synthesis

EASy Synthesis (get it)

100

What is the stereochemistry of Hydroboration oxidation and Oxymercuration oxidation addition?

No Bonus points but I'll think you're really cool if you can name the components of each reaction

Hydroboration: Syn

BH3 H2O2 NaOH

Oxymercuration Reduction: Anti

Hg(OAC)2 H2O/ NaBH4 NaOH

100

What Does the n represent in Huckel's rule?

Huckel's rule

4n+2=

The equation represents the number of pi electrons in a molecule and if n is a whole number then the molecule is aromatic

100

What are the reactants in the halogenation of benzene and what is the mechanism

Bonus points: is the addition of another substituent going to be ortho, meta, or para

(can be more than one)

X-X + FeX3 X= Cl or Bromine

Bonus points: ortho or para

(weakly meta deactivating)

100

What are the products of their reactions? Thermo or kinetic product? Faster or slower? More stable or less stable?

HBr

----------->

Temp>40* c

HBr

------------>

Temp<0* c

1. Thermo Product, faster, more stable

2. Kinetic product, slower, less stable

100

What's my product?

+ AlCl3

-------->

Alkylation carbocation can rearrange thus this is the product.

200

Which of the 2 Diels alder Reaction dienes would proceed faster

Assume Cis stereochemistry, with the software I'm using I can't make it cis, use your imagination.

The carboxylic acid is electron-withdrawing and thus decreases the reactivity of the pi bonds needed for the reaction to take place. Therefore

Option B is faster

200

Am I Aromatic? Why?

2 double bonds and 1 lone pair means 6 pi electrons, the conjugated double bonds keep it planar, and the molecule can resonate. Therefore Aromatic

200

What are the reactants in Sulfonation and Nitration and what are both of their mechanisms

Bonus points: is the addition of another substituent going to be ortho, meta, or para

(can be more than one)

Sulfonation SO3 +H2SO4

Nitration HNO3 +H2SO4

Bonus points:

Both will cause the next addition to be Meta because the positive charge on Nitrogen and partial positive of the Sulfur will push away the carbocation which means meta addition is the most stable.

200

What's my product?

+ -------> ?

Endo or Exo?

Neither endo or exo, substituents are planar thus endo or exo cannot be determined

200

Form the product

--------->

1. Nitration (causes next additions to be meta)

2. Halogenation

300

Create a frost circle for Cycloocta-1,3,5,7-tetraene

Answer sheet

300

Am I Aromatic? Why?

Not planar, 4 double bonds so 8 pi bonds, Cannot Resonate. Anti aromatic

300

Give the reactants of both Alkylation and Acylation, explain what makes them different, and why it's important to know the distinction

Alkylation: R-X + FeX3 X=Cl or Br

Acylation:

R(with some double bonded substituent )-x +FeX3 X=Cl or Br

Alkylation addition causes the next addition reaction to be either Ortho or Para

Acylation addition may add a substituent that can cause the next addition to prefer meta addition (COOH as an example) over ortho or para so be cautious.

300

What's my product (this is more of a EAS question but also kinda review)

KMNO4 ?

--------->

300

What is my product

1. (Br2 +FeBr3)

2. (HNO3 + H2SO4)

3. (CH3-CH2-Br + AlBr3)

----------------------->

Br is a halogen and thus weakly deactivates the Meta positioning of Nitro. Alkylation can't occur on Nitrobenzene thus.

Para

Ortho

400

Name all of the Benzene Derivatives (i will give partial credit)

1. 2.

3.4.

5.6.

1.Toulene (Methylbenzene)

2.styrene (Vinylbenzene)

3. Phenol (Benzenol) (Fe!nol if you're Travis Scott)

4. Anisole (Methoxybenzene)

5. Aniline (Aminobenzene)

6. Benzoic Acid

400

Am I Aromatic? Why?

3 double bonds and one lone pair that isn't in the plane of the other pi bonds thus doesn't matter. same as benzene aromatic

400

Classify each of the substituents and determine if they are Ortho/Para deactivating or Meta Deactivating

(ie where would the next addition go?)

Substituents:

-OH,-Cl,-NO2,-HSO3,-NH2,-CH2Br,-OCOOH,-COOH

Ortho/Para directing:

-OH,-Cl(slightly),-NH2,-OCOOH,-CH2Br(slightly)

Meta Directing:

-NO2,-HSO3,-COOH

400

What's my product?

--------->

(there is another minor product with same reaction but this is the major product)

1. Diels alder with (z)buta-2-ene

2. tautomerization

(occurs spontaneously for stability)

400

Form the Product

----------->

1. Acylation with Cl-COOH

2. Nitration

3. Halogenation

500

how can you transform an alkyne to a ketone?

Ultimately anything that adds a Alcohol to a alkyne so

Hydroboration Oxidation (With use of DisiamylBorane)

Acid-catalyzed hydration

Oxymercuration oxidation

(editors note: Terminal alkyne creates an aldehyde)

500

Am i Aromatic >:)

1 double bond and 4 lone pair pi electrons, 6 pi electrons, Conjugated, capable of resonance.

Aromatic

500

What's wrong with the following synthesis

1. Nitration

2. Alkylation

3. Halogenation

The positive charge on the nitrogen along with the electron-drawing nature of the NO2 group will cause the Benzene to not want to accept the Nv. However Halogenation can still occur because the +charge on the halogen is much smaller, and also because halogens are smaller then the R groups added via Alkylation

500

Form the Product