43,529 students have used Clutch for Orgo
97% got a better grade
3,804 minutes of Organic Chemistry videos

438 Video Solutions

What are the products of the following reaction based on the electron flow represented by the curved arrows?

Watch Solution

Sabinene and Δ3-carene are isomeric natural products with the molecular formula C10H16. (b) Ozonolysis of Δ3-carene gives compound B. What is the structure of Δ 3-carene?

Watch Solution

Sabinene and Δ3-carene are isomeric natural products with the molecular formula C10H16. (a) Ozonolysis of sabinene followed by hydrolysis in the presence of zinc gives compound A. What is the structure of sabinene? What other compound is formed on ozonolysis?

Watch Solution

East Indian sandalwood oil contains a hydrocarbon given the name santene (C9H14). Ozonolysis of santene gives compound A. What is the structure of santene?

Watch Solution

Compound A (C7H13Br) is a tertiary bromide. On treatment with sodium ethoxide in ethanol, A is converted into B (C7H12). Ozonolysis of B gives C as the only product. Deduce the structures of A and B. What is the symbol for the reaction mechanism by which A is converted to B under the reaction conditions?

Watch Solution

Dehydration of 2,2,3,4,4-pentamethyl-3-pentanol gave two alkenes A and B. Ozonolysis of the lower boiling alkene A gave formaldehyde (H2C=O) and 2,2,4,4-tetramethyl-3-pentanone. Ozonolysis of B gave formaldehyde and 3,3,4,4-tetramethyl-2-pentanone. Identify A and B, and suggest an explanation for the formation of B in the dehydration reaction.

Watch Solution

On the basis of the mechanism of acid-catalyzed hydration, can you suggest why the reaction would probably not be a good method for the synthesis of 3-methyl-2-butanol?

Watch Solution

On catalytic hydrogenation over a rhodium catalyst, the compound shown gave a mixture containing cis-1-tert-butyl-4-methylcyclohexane (88%) and trans-1-tert-butyl- 4-methylcyclohexane (12%). With this stereochemical result in mind, consider the reactions in (a) and (b).

(b) What two products are formed in the hydroboration–oxidation of this compound? Which one do you think will predominate?

Watch Solution

On catalytic hydrogenation over a rhodium catalyst, the compound shown gave a mixture containing cis-1-tert-butyl-4-methylcyclohexane (88%) and trans-1-tert-butyl- 4-methylcyclohexane (12%). With this stereochemical result in mind, consider the reactions in (a) and (b).

(a) What two products are formed in the epoxidation of this compound? Which one do you think will predominate?

Watch Solution

For the addition of HCl to alkenes according to the general equation given in the preceding problem, assume the mechanism involves rate-determining formation of the more stable carbocation (arrow 5 ) and predict the alkyl chloride formed by reaction of HCl with (CH 3)2C=CH2

a. (CH3)2CHCH2Cl

b. (CH3)3CCl 

Watch Solution

The overall equation for the addition of HCl to alkenes is:  

 If the transition state for proton transfer from HCl to the alkene (arrow  5 ) resembles a carbocation and this step is rate-determining, what should be the effect of alkene structure on the rate of the overall reaction?

 Fastest rate                                    Slowest rate

A. H2C=CH2    CH3CH=CHCH3    (CH3)2C=C(CH3)2

B. CH3CH=CHCH3    (CH3)2C=C(CH3)2    H2C=CH2

C. CH3CH=CHCH3    H2C=CH2    (CH3)2C=C(CH3)2

D. (CH3)2C=C(CH3)2    CH3CH=CHCH3    H2C=CH2

Watch Solution

What term best describes the relationship between an alkene and a carbocation?  

a. Isomers

b. Resonance contributors 

c. Alkene is conjugate acid of carbocation

d. Alkene is conjugate base of carbocation

Watch Solution

Based on the E1 mechanism for the conversion of a tertiary alkyl chloride to an alkene as summarized in arrows 3 and 4, which arrow(s) correspond(s) to exothermic processes? 

a. Arrow 3

b. Arrow 4

c. Both 3 and 4

d. Neither 3 nor 4

Watch Solution

Based on the E1 mechanism for the conversion of a tertiary alkyl chloride to an alkene as summarized in arrows 3 and 4, which arrow(s) represent(s) more than one elementary step? 

a. Arrow 3

b. Arrow 4

c. Both 3 and 4

d. Neither 3 nor 4

 

Watch Solution

Based on the E1 mechanism for the acid-catalyzed dehydration of a tertiary alcohol as summarized in arrows 1 and 4, which arrow(s) represent(s) more than one elementary step?

a. Arrow 1

b. Arrow 4

c. Both 1 and 4

d. Neither 1 nor 4

Watch Solution

Based on the SN1 mechanism for the reaction of tertiary alcohols with HCl as summarized in arrows 1 and 2, which arrow(s) represent(s) more than one elementary step? 

a. Arrow 1

b. Arrow 2

c. Both 1 and 2

d. Neither 1 nor 2

Watch Solution

Compound A (C6H14) gives three different monochlorides on photochemical chlorination. One of these monochlorides is inert to E2 elimination. The other two monochlorides yield the same alkene B (C6H12) on being heated with potassium tert -butoxide in tert -butyl alcohol. Identify compound A, the three monochlorides,and alkene B. 

Watch Solution

Acid-catalyzed dehydration of 2,2-dimethyl-1-hexanol gave a number of isomeric alkenes including 2-methyl-2-heptene as shown in the following equation.

(a) Write a stepwise mechanism for the formation of 2-methyl-2-heptene, using curved arrows to show the fl ow of electrons.

Watch Solution

In Problem 5.20 (Section 5.13) we saw that acid-catalyzed dehydration of 2,2- dimethylcyclohexanol afforded 1,2-dimethylcyclohexene. To explain this product we must write a mechanism for the reaction in which a methyl shift transforms a secondary carbocation to a tertiary one. Another product of the dehydration of 2,2-dimethylcyclohexanol is isopropylidenecyclopentane. Write a mechanism to rationalize its formation, using curved arrows to show the flow of electrons. 

 

Watch Solution

Write a sequence of steps depicting the mechanisms of each of the following reactions. Use curved arrows to show electron flow.

 

Watch Solution

Write a sequence of steps depicting the mechanisms of each of the following reactions. Use curved arrows to show electron flow.

 

Watch Solution

Write a sequence of steps depicting the mechanisms of each of the following reactions. Use curved arrows to show electron flow.  

 

Watch Solution

Each of the following carbocations has the potential to rearrange to a more stable one. Write the structure of the rearranged carbocation, and use curved arrows to show how it is formed.

 

Watch Solution

Each of the following carbocations has the potential to rearrange to a more stable one. Write the structure of the rearranged carbocation, and use curved arrows to show how it is formed. 

Watch Solution

Each of the following carbocations has the potential to rearrange to a more stable one. Write the structure of the rearranged carbocation, and use curved arrows to show how it is formed. 

Watch Solution