Organic Chemistry
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cis-4-iodocyclohexanethiol and trans-4-iodocyclohexanethiol produce different substitution products in a reaction with HO−. Draw the mechanisms that explain the formation of different substitution products.
Determine which compound from each of the following pairs will form a cyclic ether more rapidly when deprotonated.
Draw the major products expected from each of the following reactions.
Draw a suitable mechanism for the following intramolecular reaction.
Draw a suitable mechanism for the following reaction.
(Note: replacing the nitrogen atom with –CH– slows down the reaction)
Identify the compound which would undergo elimination more rapidly.
Explain how the rate of the reaction of 1-bromopropane with sodium ethoxide in DMF changes when:
a. The concentrations of both 1-bromopropane and sodium ethoxide are doubled.
b. Ethanol is used as the solvent instead of DMF.
Explain how the rate of the reaction of 2-bromo-2-methylpentane with methanol changes.
a. When we change the alkyl halide to 2-chloro-2-methylpentane.
b. When we change the alkyl halide to 2-chloro-3-methylpentane.
The reaction shown below involves a step where the hydroxy group in the reactant is converted to a good leaving group via protonation. Propose a reasonable mechanism for the reaction.
Two different elimination products can be obtained when the following compound is reacted with sodium methoxide in methanol solvent. Explain why the deuterated product predominates by about a 7:1 ratio.
Identify the alkyl halides that would give the following pure alkenes through E2 dehydrohalogenation.
a. But-1-ene
b. 2-Methylbut-1-ene
c. Hept-3-ene
Draw the arrow-pushing mechanism for the elimination reaction shown below. Identify if the mechanism is an E1 or an E2 mechanism.
Predict the product of the elimination reaction below.
Predict the product(s) that would form when the given molecule is allowed to react under the following condition(s). If no reaction occurs, write "no reaction".
Predict the product(s) of the given conditions below. If no reaction occurs, write “NR”.
Draw the products when given alcohol reacts with (a) 1. TsCl, Et3N 2. NaOt-Bu and with (b) H2SO4. If there are no reactions, write "No Reaction."
Draw the product(s) formed when the starting compound is allowed to react under the given acidic conditions. Write "NR" if there is no reaction.
Predict the product(s) that would result when the starting molecule is treated with 2 equivalents each of HCl and HBr.
Draw the compound(s) that would form when the starting organic compound is allowed to react under the following conditions. If there is no reaction, write “NR”.
Draw the product(s) that would result from the reaction of the given molecule with PBr3.
Give the product(s) that would form when the given molecule is subjected to the following reaction conditions. Write “NR” if there is no reaction.
What is the product of the substitution/elimination reaction below? Take into consideration the configuration of the product.
Determine the product of the substitution/elimination reaction below.
Draw the product/s of the reaction below. Take into consideration the configuration of the product/s.
Determine if the given bases would favor either E1 or E2 reaction.
Draw the mechanism and label the following as an E1 or E2 elimination reaction.
Determine if the reactant shown will undergo E1 or E2 elimination.
Determine the type of catalysis involved in the slow step of the sequence below.
Identify the type of catalysis involved in the slow step of the sequence below.
Identify the reaction with a greater ratio of a substitution product to an elimination product:
a. A reaction of 2-bromopentane with Cl−
b. A reaction of 2-bromopentane with I−
4-(4-(bis(2-chloroethyl)amino)phenyl)butanoic acid is a nitrogen mustard analog. Why is it a good cancer drug?
The molecules below were studied as possible alkylating agents in an aqueous environment. One was found to be too unreactive and one was found to be too insoluble. Identify the one that is expected to work best.
Provide a mechanism for the formation of the four products in the given reaction. Use curved arrows to show the movement of electrons during deprotonation and/or nucleophilic attack by the solvent. (Curved arrows do not show the movement of protons or other species.)
What are the products of the following reaction?
1-bromo-2,3-dimethylcyclopentane + silver nitrate in water (AgNO3 forces ionization)
Provide the products formed. Note: Syn-coplanar E2 eliminations are rare, usually occurring when free rotation is not possible.
Deuterium (D) is a hydrogen isotope that has a mass of 2. Its chemical properties are very similar to hydrogen. In a rate-limiting step, breaking a C-D bond causes slower reaction rates due to its higher strength (5.0 kJ/mol or 1.2 kcal/mol) than the C-H bond. The effect on rate is known as the kinetic isotope effect. When the β-hydrogens of the following compound are deuterated, the rate of formation of the substitution product remains constant, while the rate of formation of the elimination product for the deuterated compound is slower. Explain.
Suggest a reagent that would form cycloheptene from each of the following compounds.
(i) cycloheptyl chloride
(ii) cycloheptanol
Propose a method to synthesize the given 1° alcohol from a 1° alkyl bromide.
In a solvolysis reaction, SN1 and E1 mechanisms often compete. Draw the mechanism and the plausible products for the solvolysis of 2-chloro-2,3,3-trimethylpentane in ethanol. [Stereochemistry is ignored.]
Provide the conditions and a chloroalkane needed to produce the following alkene.
What causes the inefficiency of the SN2 reaction used to synthesize the given ether?
There are three different possible elimination reactions. The E1 and E2, which are the most commonly encountered, are two of them. The E1cb is the third. Below is an example of this.
What factors favor the E1cb mechanism in the given conditions?
