a)
Interpretation:
Assuming that halogens add to
Concept introduction:
Alkynes when treated with one equivalent of a halogen yield a dihaloalkene as the product. They react with two equivalents of the halogens to yield a tetrahaloalkane derivative. In the first step of the addition reaction the nucleophilic attack of the π electrons of the double/triple bond in alkene/alkyne on a halogen results in the formation of a cyclic halonium ion with the simultaneous elimination of a halide ion. In the second step the halide ion attacks the cyclic halonium ion to yield the product.
To propose:
A mechanism and to predict the product(s) expected for the reaction in which two equivalents of Br2 adds to 2-butyne assuming that bromine adds to alkynes in the same manner as they add to alkenes.
b)
Interpretation:
Assuming that halogens add to alkynes in the same manner as they add to alkenes, a mechanism is to be proposed and the product(s) expected for the reaction in which two equivalents of Cl2 adds to 1-phenylpropyne is/are to be predicted.
Concept introduction:
Alkynes when treated with one equivalent of a halogen yield a dihaloalkene as the product. They react with two equivalents of the reagents to yield a tetrahaloalkane as the product. In the first step of the addition reaction, the nucleophilic attack of the π electrons of the double/triple bond in alkene/alkyne on a halogen results in the formation of a cyclic halonium ion with the simultaneous elimination of a halide ion. In the second step the halide ion attacks the cyclic halonium ion to yield the product.
To propose:
A mechanism and to predict the product(s) expected for the reaction in which two equivalents of Cl2 adds to 1-phenylpropyne assuming that chlorine adds to alkynes in the same manner as they add to alkenes.
c)
Interpretation:
Assuming that halogens add to alkynes in the same manner as they add to alkenes, a mechanism is to be proposed and the product(s) expected for the reaction in which two equivalents of Br2 adds to 1-pentyne is/are to be predicted.
Concept introduction:
Alkynes when treated with one equivalent of a halogen yield a dihaloalkene as the product. They react with two equivalents of the reagents to yield a tetrahaloalkane as the product. In the first step of the addition reaction the nucleophilic attack of the π electrons of the double/triple bond in alkene/alkyne on a halogen results in the formation of a cyclic halonium ion with the simultaneous elimination of a halide ion. In the second step the halide ion attacks the cyclic halonium ion to yield the product.
To propose:
A mechanism and to predict the product(s) expected for the reaction in which two equivalents of Br2 adds to 1-pentyne assuming that bromine adds to alkynes in the same manner as they add to alkenes.
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Chapter 9 Solutions
Organic Chemistry
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- Draw the structure of the expected organic product(s) formed in the following reactions including correct stereochemistry. If the product is racemic write racemic or draw both isomers. Assume all reagents listed are present in excess unless otherwise noted. If no reaction occurs, state "No Reaction''.arrow_forwardShown below is a carbocation intermediate in an electrophilic addition reaction of HCl with two different alkenes. Draw structural formulas for both of the alkenes.arrow_forwardDraw the structure of the expected organic product formed in the following reactions including correct stereochemistry. If the product is racemic indicate this by either drawing both isomers or drawing one and writing racemic. Assume all reagent are present in excess unless otherwise noted. If no reaction occurs, state "No Reaction".arrow_forward
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- Haloalkanes undergo nucleophilic substitution whereas haloarenes undergo electrophilic substitution. Explain.arrow_forwardSynthesize this molecule by using the principles of radical reactions, substitution, addition, and elimination reactions.Start with ethyne.arrow_forwardThe Friedel-Crafts Alkylation of p-xylene n-propyl bromide can result in an isopropyl as well as n-propyl substitution. A) Write the chemical equation involved in this reaction. B) Which will be the major and minor product? What do you expect will be the ratio of n-propyl to isopropyl substitution for p-xylene?arrow_forward
- Chemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage Learning