Leaving Group Conversions Summary Practice Problems

In each case, show how alcohol can be converted into the given halides (chloride, bromide, and iodide).
a. 1-halopropane (halo = chloro, bromo, iodo)
b. halocyclohexane

Predict the expected products when the following two alcohols are treated with each of the given reagents.
Reagents: (1) HCl, ZnCl₂; (2) HBr; (3) PBr₃; (4) P/I₂; and (5) SOCl₂.
Alcohols: a. propan-1-ol ; b. 2-methylpropan-2-ol

Show the reaction to convert (S)-pentan-2-ol into the following products.
a. (S)-2-chloropentane.
b. (R)-2-bromopentane.
c. (R)-pentan-2-ol.

Consider the following reaction:

Is the product shown the correct expected product from the reaction? If not, draw the correct product and provide the proper reagent that must be used.

Provide a proper reagent for the reaction shown below:

Which of the following reagents can be used to transform a primary alcohol into a primary alkyl halide?

Which of the following reagents listed below can be used to carry out the following reaction?

Using cyclopentanone as the starting molecule, propose a synthesis for the following molecule.

Draw the major products formed from the reaction of cis-3-ethylcycloheptanol with the reagents below. Include stereochemistry, if applicable.

(i) concentrated HBr

(ii) TsCl/pyridine, then NaBr

Propose a synthesis for the following compound starting with any alcohol containing a maximum of six carbons as the organic material.

When cis- and trans-2-methylcyclopentanol undergo dehydration in warm sulfuric acid, the major alkene product formed is 1-methylcyclopent-1-ene. When the conversion to alkene is done via tosylation using TsCl and pyridine, followed by elimination using NaOCH₃ (strong base), the two alcohols give different alkene products. The tosylate of cis-2-methylcyclopentanol forms mostly 1-methylcyclopent-1-ene, while trans-2-methylcyclopentanol only forms 3-methylcyclopent-1-ene. Explain how the regiochemical difference in the products is controlled by a stereochemical difference in the reactants.

Give the major products formed from the reaction of cis-3-methylcyclopentanol with each of the following reagents. Include stereochemistry.

(a) PCl₃

(b) SOCl₂

(c) Lucas reagent

Suggest how cis-3-methylcyclopentanol can be converted into the following products.

a. cis-1-chloro-3-methylcyclopentane
b. trans-1-chloro-3-methylcyclopentane

Showing stereochemistry, determine the products of the reactions below.

Show the stereoisomers that could be generated given the following reaction conditions.

When SOCl₂ replaces HCl in the reaction, it only produces one product. Explain why.

Using (R)-1-deuterio-1-pentanol as the starting substrate, determine how to prepare (S)-1-deuterio-1-methoxypentane.

Show how to synthesize each ether shown below using simple alcohol as the starting material.
(i) 1-methoxypropane
(ii) 2-methoxy-2-methylpropane
(iii) benzyl cyclohexyl ether

Show how each of the following compounds can be synthesized from but-1-ene.
(i) 2-methoxybutane
(ii) 1-ethoxybutane
(iii) 1-methoxybutan-2-ol