Organic Chemistry
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Determine the major product of the monohalogenation reaction of the alkane given below. State whether you believe the reaction is selective and explain why.
Reaction (a) shown below produces an unequal mixture of products while reaction (b) produces an equal (racemic) mixture of products. Explain why.
In the following free radical halogenation reaction, one of the products is formed in excess. Identify which stereoisomer is the major product.
In the following free radical halogenation reaction, one of the products is formed in excess. Explain why this reaction yields an unequal mixture of products.
Predict the missing products in the free radical halogenation reaction shown below. Ignore stereoisomers.
Is it possible to make the following primary bromoalkane in good yield using the alkane halogenation reaction? Justify your answer.
Draw the major product obtained in the free radical halogenation reaction given below.
What would be the major product formed in the free radical bromination reaction given below?
Draw a suitable mechanism for the free radical bromination reaction given below.
Consider the following reaction and identify the weakest bond (a, b, or c) in the given molecule.
Determine why the marked bond in the following reaction is the weakest bond.
Draw a plausible mechanism for the following chlorination reaction. Hint: The movement of a single electron is represented using a fishhook arrow.
Predict the number of alkyl bromides expected from the monobromination of the alkane given below. Do not include stereoisomers.
Determine the number of alkyl bromides expected from the monobromination of the alkane given below. Do not include stereoisomers.
How many monobrominated products are expected from the alkane given below? Do not include stereoisomers.
Determine the number of alkyl chlorides expected from the monochlorination of the alkane given below. Do not include stereoisomers.
Determine the number of alkyl bromide expected from the monobromination of the alkane given below. Do not include stereoisomers.
Predict the number of alkyl halides expected from the monobromination of the alkane given below. Include stereoisomers.
Predict the number of alkyl bromides expected from the monobromination of the alkane given below. Include stereoisomers.
Determine the number of alkyl halides expected from the monobromination of the alkane given below. Include stereoisomers.
Determine the number of alkyl halides expected from the monochlorination of the alkane given below. Include stereoisomers.
Determine the number of alkyl bromides obtained from the monobromination of the alkane given below. Include stereoisomers.
Draw the product of the following reaction.
Draw the monochlorinated product obtained in the given reaction. Do not show stereochemistry.
Draw the product obtained from the given reaction. No need to show stereochemistry.
Draw the possible product(s) of the given monochlorination reaction. Do not show stereochemistry.
What is the major monobrominated product formed when the following compound is heated with NBS? Disregard stereoisomers.
Draw the major monochlorinated product obtained in the following reaction. Disregard stereoisomers.
What is the major product of the following reaction? No need to include stereoisomers.
What is the major product of the following reaction? Do not include stereoisomers.
Which isomer with the formula C7H16 forms only three monobrominated products (one primary, one secondary, and one tertiary)? Two of these products are achiral and one is chiral.
Which isomer with the formula C7H16 forms only three monobrominated products? All of these products are achiral.
Why does iodine not react with methane under ordinary conditions, even though I2 is cleaved easily to form radicals?
Draw the major monobrominated product(s) obtained in the reaction given below. Include stereochemistry if applicable.
Write the mechanism of the monochlorination of cyclopentane, including initiation, propagation, and termination.
When propane is chlorinated, a mixture of products is obtained. Draw the structures of all the monochlorinated products present in this mixture.
Draw all the possible monochlorinated products for each of the following alkanes.a. 2-methylbutaneb. 2,2-dimethylpropane
Which monobrominated product would be produced in good yield by the free-radical bromination of the following alkanes?a. 2-methylbutaneb. 2,2-dimethylpropane
Cyclopentane undergoes light-promoted chlorination as shown below. Propose a mechanism for this reaction and label the initiation and propagation steps.
When one mole of bromine is mixed with one mole of methane in the presence of light, then a mixture of di- tri- and tetrabromomethane is obtained along with some unreacted methane.(a) Explain why a mixture of products is formed even if the reactants were in the same stoichiometric ratio.(b) Show how these compounds are formed from bromomethane.
Hydrogen peroxide is often used as an initiator in free-radical chlorination reactions because the oxygen-oxygen bond undergoes homolytic cleavage easily compared to the chlorine-chlorine bond.Propose a mechanism for the H2O2-initiated chlorination of cyclohexane.
Propose a free-radical halogenation reaction to synthesize each of the compounds given below. Also, provide a reason why we get a single major product in each of these reactions.a. 1-Chlorocyclopentaneb. 2-Bromo-2-methylpentane
Explain how would an industry control the ratio of methane and bromine.a. To synthesize a good amount of CBr4?b. To synthesize a good amount of CH3Br?
When pentane is reacted with chlorine in the presence of light, a poor yield of 1-chloropentane is obtained. However, cyclopentane can be converted to chlorocyclopentane with good yield by the same reaction.a. Explain this difference.b. What should be the ratio of reactants to get a good yield of chlorocyclopentane.
Cyclopropanes tend to open up in the presence of nearby radicals because of angle strain. Draw a mechanism for the reaction below.
Tributyltin hydride, (C4H9)3SnH, is often used as a “chain propagating radical”. Is the Sn ― H or C― H expected to be stronger? Which one will form a more stable radical? Justify your answer.
For the reaction below, draw the major monohalogenation product(s). Identify if the reaction is selective and justify it.
Give the monohalogenation product(s) of the reaction shown below. If the reaction is selective, draw only the major product(s). Otherwise, draw all possible products.
Provide the monohalogenation product(s) of the reaction shown below. If the reaction is selective, draw only the major product(s). Otherwise, draw all possible products.
Choose the best reaction to represent the properties of radical halogenation.
Draw the arrow-pushing mechanism for the bromination of cyclopentane. Only draw three possible termination steps.
Draw the arrow-pushing mechanism, including the initiation and the two propagation steps for the following reaction.
Supply the products in the free radical halogenation reaction given below. Do not include stereoisomers.
ACBN is a molecule that can be used as an initiator in a radical reaction. Draw the mechanism of the formation of the given radical molecule and determine the driving force for this reaction.
As shown below, a haloalkane can be reduced into an alkane using Bu3SnH and AIBN.
Draw the mechanism of the reaction.
In carrying out radical cyclization, we can use Bu3SnH and a small amount of AIBN. Draw the mechanism for the following cyclization reaction.
An alkane has a molecular formula of C8H18 and can only form a single product when it reacts with Cl2 under light. Draw its structure.
In the presence of an acid catalyst, formaldehyde forms a trimer known as trioxane. Propose a mechanism for the formation of trioxane.
Draw the mechanism for the reaction below.
Consider the bromination of isobutane. Will the rate of the reaction increase, decrease, or remain unchanged when HBr is added to the reaction mixture? Explain your answer.
Determine the number of products formed by the monochlorination reaction of the following alkane when stereoisomers are included.
Determine the number of products formed by the monochlorination reaction of the given alkane, including stereoisomers.
Determine how many products would be obtained from the cycloalkane's monochlorination reaction if all its stereoisomers are included.
Determine the major product for the reaction of the given cycloalkane with Cl2 in UV light. Ignore stereochemistry.
How many products are formed from the radical chlorination of methylcyclopentane? (Ignore stereoisomers.)
True or false. The following steps are involved in the formation of tetrabromomethane (CBr4) from the reaction of methane with Br2 in the presence of light:
Consider the mechanisms for the monobromination of methane involving the propagation steps shown below:
How do you know the monobromination reaction does not occur via the alternative mechanism?
Synthesize cycloheptene from cycloheptane (not by dehydrogenation).
Why is the following free-radical chlorination of ethane incorrect based on experimental evidence?
Consider the following free-radical chlorination:
What is its mechanism?
Consider the second propagation step in the chlorination of ethane:
What is the structure of its transition state? Is the transition state reactant-like or product-like? Which partial bond in the transition state is stronger?
Consider the free radical iodination of ethane,
Provide two reasons why iodine does not react favorably with ethane.
Consider the following abstraction of a secondary hydrogen and a primary hydrogen from butane using an iodine radical:
What is the enthalpy of reaction for each abstraction?
In general, alkyl radicals are less stable than alkoxy radicals. (i) What is the equation for the alkyl free radical abstraction of the alcohol hydrogen atom from 2-methylbutan-2-ol? (ii) What is the reason for being able to use 2-methylbutan-2-ol as an antiknock additive in gasoline?
Using the provided starting material, devise the synthesis pathway for the given compound.
You are conducting a chlorination reaction where 1 mole of ethane is mixed with 1 mole of chlorine. The products contain significant amounts of monochlorinated and polychlorinated products, along with unreacted ethane. How would you modify the experiment to obtain a good ethane conversion to C2H5Cl? Of ethane to C2Cl6?
Provide the initiation step reaction for the monobromination of methane.
The proposed mechanism for the free-radical chlorination of ethane is incorrect. Provide empirical evidence to demonstrate the inaccuracies of this mechanism.
Draw the reaction mechanism for the free-radical iodination of propane to yield 2-iodopropane. Determine the ΔH° of each step and the total ΔH° for this reaction.
Draw all the possible monobrominated derivatives of each of the alkanes listed below.
a. 2-methylpropane
b. 2-methylbutane
Determine whether the free-radical monobromination of each alkane listed below produces a single product.
a. cyclohexane
b. propane
The free-radical halogenation reaction usually generates a mixture of substitution products. Rationalize.
Predict how many dibrominated products each of the following compounds can produce (including stereoisomers).
a. CH2=CH—CH=CH2
b. CH3C≡CCH3
Predict how many monobrominated products each of the following compounds can produce.
a. (CH3)2C=CHC≡CH
b. CH2=CH-C≡CCH3
The following compound undergoes free radical bromination at the benzylic position. Give the mechanism for the monobromination of the given compound and draw the two stereoisomer products.Also, assign R and S configurations to the asymmetric carbon atoms in the products.
Consider the following transformation:
Propose the mechanism for the reaction.
Drugs and other exogenous molecules can be excreted by the human body through a reaction similar to autoxidation. What makes the following molecule susceptible to autoxidation?
For the reaction of 1-isobutylcyclohex-1-ene with the following reagents, show the stereoisomers of the major product.
(i) NBS/∆/peroxide
(ii) Br2/CH2Cl2
Ethers have the tendency to form explosive peroxides. Draw a plausible mechanism for the peroxide formation from the given ether. Assume the presence of a radical X• to begin the reaction.
Which of the following ethers most readily produces peroxide?
Among the following ethers, identify the one which is least apt to produce peroxide.
Write an equation with fishhook arrows that shows the formation of a relatively stable free radical from ascorbic acid and methyl free radical.
A graduate student was studying free radical halogenation reactions. She added NBS to a solution of 3-methylcyclopent-1-ene and irradiated the mixture with a sunlight lamp. After all of the added NBS was consumed, she found that the reaction resulted in four different isomeric products of the formula C6H9Br. Assuming that a Br radical initiates the reaction by abstracting an H atom, write chemical equations and draw the structures of four different radicals.
Show the major products of free-radical bromination for each of the compounds given below. Keeping in mind that the bromination is highly selective towards the stable radical formation.a. Methylcyclohexaneb. Cyclopentane
Use the bond-dissociation energies from the given table to determine whether the chlorination of propane would be selective or not.
Determine the product with the most yield for the reaction below. Disregard stereoisomers.
True or False: Radical addition to alkenes is as effective for the synthesis of flouroalkanes as it is for bromoalkanes. Justify your answer using your knowledge of the mechanism of this reaction, along with bond dissociation energies.
Benzylic cations, anions,and radicals are all more stable compared to simple alkyl intermediates.2-bromotoluene reacts with bromine in the presence of light to give a benzyl bromide derivative. Propose a plausible mechanism for this reaction.
Demonstrate how you would synthesize 2-chloro-2-methylpropane from isobutane.