OCHEM Lab Midterm review

IV

3. Identify the expected major product of the following reaction. (methylcyclohexene)

1) BH3, THF 2) NaOH, H2O2, H2O

7. What reagent(s) would accomplish the following synthesis?

A- I

8. What is the expected major product for the following reaction sequence? (hydroboration)

1. BH3∙THF; 2. H2O2, NaOH

9. Which reagents are most likely to accomplish the reaction shown below? (hydroboration)

Isolated double bond

A molecules in which more than one single bond separates two double bonds are called as

- less substituted carbon - more substituted carbon - more substituents - nucleophile

According to Markovnikov's rule of the electrophilic addition to an alkene, the electrophile, usually a proton, is more likely to add to the ___ in a double bond. This arrangement places the intermediate carbocation on the ___, which stabilizes it with the presence of ___. In the major product of a reaction following Markovnikov's rule, the ___ will then end up on the more-substituted carbon in a double bond.

Dienophile

Conjugated diene reacts with which among the following to form a cyclohexene?

Not possible

Determine whether each alcohol could be a major product of the acid-catalyzed hydration of an alkene.

Possible

Determine whether each alcohol could be a major product of the acid-catalyzed hydration of an alkene. 2

Not possible product

Determine whether each alcohol could be a major product of the acid-catalyzed hydration of an alkene. 3

Possible product

Determine whether each alcohol could be a major product of the acid-catalyzed hydration of an alkene. 4

Oxidation (adds oxygen or loses hydrogen) Reduction (adds hydrogen or loses oxygen)

Determine whether each pictured reaction represents an oxidation or a reduction of the organic reactant.

Conjugated

Dienes with pi bonds separated by exactly one sigma bond are classified as

4

How many reducing equivalents are present in each unit of sodium borohydride NaBH4

- stir bar and stir plate - boiling chips or stone

Identify items that can be used to control the boiling when heating liquid in a round bottom flask

- Dissolves a sample well at a high temperature - Does not dissolve a sample well at low temperature

Identify the characteristics of a good recrystallization solvent.

B

Identify the diene and dienophile expected to produce the Diels-Alder product shown in the box below C=o

II - B

Identify the diene and dienophile expected to produce the Diels-Alder product shown in the box below. (2 pentanes and C=o)

IV

Identify the diene and dienophile expected to produce the Diels-Alder product shown in the box below. CN

III

Identify the diene and dienophile expected to produce the Diels-Alder product shown in the box below. COO

I

Identify the diene and dienophile expected to produce the Diels-Alder product shown in the box below. COOO

III - C

Identify the diene and dienophile expected to produce the Diels-Alder product shown in the box below. c=o and CN

III

Identify the expected major product of the following Diels-Alder reaction - OCH3

IV

Identify the expected major product of the following Diels-alder reactions CN

A

Identify the expected major product of the following Diels-alder reactions Cl O

D-- IV

Identify the expected major product of the following reaction (H30)

III

Identify the expected major product of the following reaction (H30, H2O)

II

Identify the major product of the following Diels-Alder Reaction

SN2 mechanism

Identify the mechanism for the Williamson ether synthesis

1,4 pentadiene

Identify the one which is the perfect example for Isolated double bond?

Cyclic dienes react very slow than the linear chain dienes

Identify the statement which is related to Diels-Alder Reaction?

III -- C

Provide the reagents necessary to prepare the following compound using a Williamson ether synthesis.

IV --D

Provide the reagents necessary to prepare the following compound using a Williamson ether synthesis.

A reaction where all changes in bonding (bond making and bond breaking) occur simultaneously

The Diels Alder reaction is a concerted reaction. Define concerted.

D - IV

The following product shown in the box is formed by an intramolecular Diels-Alder reaction. Identify the structure of the starting compound.

syn, anti-markiovnikov

The mechanism of hydroboration-oxidation must explain the observed____ addition of the H and OH to the alkene as well as the _____ regiochemistry (BH3 turns into BH2 and attaches to alkene on the less substituted Carbon while the other H attaches on the more substituted Carbon, the BH2 is oxidized and replaced with OH therefore making it?)

Diels-Alder Reaction

The reactant shown below can follow which type of reaction mechanism

Anti-Markovnikov orientation with syn-addition

The regioselectivity and stereospecificity in the hydroboration-oxidation of an alkene is best described as

Assessment of sample's purity

What are the reasons to determine the melting point of a sample in a melting point apparatus?

Condenser

What is A?

Round bottom flask

What is B?

Water outlet

What is C?

Any atom other than C or H

What is a heteroatom in an organic compound?

cycloaddition

What is the correct classification of the following pericyclic reaction?

II -- B

What is the expected major product for the following reaction sequence? (2,5 dimethyl-2hexene)

3

What is the major product obtained from the following reaction?

take away double bond and add BH2

What is the product of the reaction?

take away double bond and add OH

What is the product of the reaction? 2

take away double bond and add OH leave hexane

What is the product of the reaction? 3

take away double bond and add OH leave methyl and pentane

What is the product of the reaction? 4

III and IV

What reactants are necessary to make the product? (DA reaction)

Dilute aqueous H2SO4

What would be the opitmal conditions to achieve the following synthesis

Any newly-added drying agent remains a powder, instead of clumping up

When drying an organic solution, how is it determined that enough drying agent has been added

- When the gloves have been exposed to a solvent - When there is any visible tear in the gloves

When should you replace your gloves in an organic lab?

As low as possible, no more than halfway up

When working in a fume hood, what is the best position of the hood sash

Carboxylic acid

Which class of compound is an example of a carbonyl compound

C

Which is unreactive in hydride reduction with NaBH4?

All of them

Which of the compounds shown is(are) classified as ethers?

Alcohol

Which of the following functional groups indicated by a strong and broad infrared absorption around 3300 cm-1?

B

Which of these molecules could not be made using a Diels-Alder reaction

II and IV

Which of these structures is a conjugated diene?

D

Which pairing of diene and dienophile would lead to the product shown?

A proper support, such as a cork ring, should be set in place

Which task must be carried out before using a round-bottom flask at the lab bench?

It is a good source of the hydride ion (H)

Why is sodium borohydride an important reagent in reducing a ketone?

Water inlet

what is D?

C=O

which feature represents a carbonyl group?