Chapter 24, Problem 24.57P

Interpretation Introduction

(a)

Interpretation:

The organic product of the given reaction is to be drawn.

Concept introduction:

Multiple bonds in alkenes and alkynes are cleaved when treated with hot, concentrated permanganate in a basic solution in an oxidative cleavage reaction. Both carbons of the alkene or alkyne are oxidized in the process to carbonyl groups or carbon dioxide. The final functional group that is formed depends on the reaction conditions. The permanganate ion is added across the multiple bonds in a way similar to the Diels-Alder reaction, a $[4+2]$ cycloaddition. This is followed by a $[4+2]$ cycloelimination that breaks the $\text{C}-\text{C}$ bond, eliminating ${\text{MnO}}_{\text{2}}$. The two carbons are converted to carbonyl groups in this step. If these carbons have two alkyl groups bonded to them, they are converted to ketone groups. If only one alkyl group is present, the carbon is converted to an aldehyde. Aldehyde groups are further oxidized to carboxylate group under the reaction conditions. This may be converted to a carboxylic acid by an acid workup. If there are no alkyl groups attached to the carbon, it is completely oxidized to carbon dioxide.

Answer to Problem 24.57P

The structure of the product of the given reaction is

Explanation of Solution

The given reaction is

Hot, concentrated permanganate (${\text{KMnO}}_4$) will cleave the double bond, oxidizing the two carbon atoms to carbonyl groups. Both carbon atoms are secondary, so they are initially converted to aldehyde groups which are then further oxidized to carboxylic acid groups. The carboxylic acid groups are immediately deprotonated because of the strongly basic conditions. The acid workup will then recover the carboxylic acid groups.

Therefore, the product of the reaction is

Conclusion

The products of the reaction were determined on the basis of the cleavage of the double bond by hot concentrated permanganate in basic medium and the oxidation of the two carbons to carbonyl groups.

Interpretation Introduction

(b)

Interpretation:

The organic product of the given reaction is to be drawn.

Concept introduction:

Multiple bonds in alkenes and alkynes are cleaved when treated with hot, concentrated permanganate in a basic solution in an oxidative cleavage reaction. Both carbons of the alkyne are oxidized in the process to carboxyl groups. The end carbon of a terminal alkyne is oxidized completely to carbon dioxide. The final functional group that is formed depends on the reaction conditions. The permanganate ion is added across the multiple bonds in a way similar to the Diels-Alder reaction, a $[4+2]$ cycloaddition. This is followed by a $[4+2]$ cycloelimination that breaks the $\text{C}-\text{C}$ bond, eliminating ${\text{MnO}}_{\text{2}}$. The two carbons are converted to carbonyl groups in this step. If these carbons have two alkyl groups bonded to them, they are converted to ketone groups. If only one alkyl group is present, the carbon is converted to an aldehyde. Aldehyde groups are further oxidized to the carboxylate group under the reaction conditions. This may be converted to a carboxylic acid by an acid workup. If there are no alkyl groups attached to the carbon, it is completely oxidized to carbon dioxide.

Answer to Problem 24.57P

The structure of the organic product of the given reaction is

Explanation of Solution

The given reaction is

Hot, concentrated permanganate (${\text{KMnO}}_4$) will cleave the triple bond, oxidizing the two carbon atoms to carboxyl groups. The terminal carbon is further oxidized to carbon dioxide. The carboxylic acid group is immediately deprotonated because of the strongly basic conditions. The acid workup will then recover the carboxylic acid groups.

Therefore, the organic product of the reaction is

Conclusion

The products of the reaction were determined on the basis of the cleavage of the triple bond by hot concentrated permanganate in basic medium and the oxidation of the internal carbon to carboxylic acid and the terminal carbon to carbon dioxide.

Interpretation Introduction

(c)

Interpretation:

The organic product of the given reaction is to be drawn.

Concept introduction:

Multiple bonds in alkenes are cleaved when treated with ozone in a reaction called ozonolysis. Both carbons of the alkene are oxidized in the process to carbonyl groups. Ozone adds across the double bond in a $[4+2]$ cycloaddition step to form a molozonide with an $-\text{O}-\text{O}-\text{O}-$ bridge across the initial double-bonded carbons. The next two steps, a $[4+2]$ cycloelimination followed by another $[4+2]$ cycloaddition converts the molozonide to an ozonide, in which the alkene double bond is completely replaced, by one $-\text{O}-\text{O}-$ and one $-\text{O}-$ bridge. to The final functional group that is formed depends on further processing. Reduction of the ozonide with $\text{Zn, HOAc}$ or ${{\text{(CH}}_{\text{3}}\text{)}}_{\text{2}}\text{S}$ results in the formation of a compound with ketone or aldehyde groups. Oxidation with ${\text{H}}_{\text{2}}{\text{O}}_{\text{2}}$ results in oxidizing the aldehyde group, if present, to a carboxylic acid.

Answer to Problem 24.57P

The structures of the products of the given reaction are

Explanation of Solution

The given reaction is

Ozone will add across the double bond to initially form a molozonide. The molozonide rearranges to an ozonide following a cycloelimination and a cycloaddition. The ozonide is then reduced by zinc-acetic acid to cyclohexanone and propanal.

Therefore, the products of the reaction are

Conclusion

The products of the ozonolysis reaction were determined on the basis of cleavage of the double bond and oxidation of the two carbons to carbonyl groups.

Interpretation Introduction

(d)

Interpretation:

The organic product of the given reaction is to be drawn.

Concept introduction:

Multiple bonds in alkenes are cleaved when treated with ozone in a reaction called ozonolysis. Both carbons of the alkene are oxidized in the process to carbonyl groups. Ozone adds across the double bond in a $[4+2]$ cycloaddition step to form a molozonide with an $-\text{O}-\text{O}-\text{O}-$ bridge across the initial double-bonded carbons. The next two steps, a $[4+2]$ cycloelimination followed by another $[4+2]$ cycloaddition converts the molozonide to an ozonide, in which the alkene double bond is completely replaced, by one $-\text{O}-\text{O}-$ and one $-\text{O}-$ bridge. The final functional group that is formed depends on further processing. Reduction of the ozonide with $\text{Zn, HOAc}$ or ${{\text{(CH}}_{\text{3}}\text{)}}_{\text{2}}\text{S}$ results in the formation of a compound with ketone or aldehyde groups. Oxidation with ${\text{H}}_{\text{2}}{\text{O}}_{\text{2}}$ results in oxidizing the aldehyde group, if present, to a carboxylic acid.

Answer to Problem 24.57P

The structures of the organic products of the given reaction are

Explanation of Solution

The given reaction is

Ozone will add across the double bond to initially form a molozonide. The molozonide rearranges to an ozonide following a cycloelimination and a cycloaddition. One of the carbons of the double bond is oxidized initially to an aldehyde which is further oxidized to a carboxylic acid on treatment with ${\text{H}}_{\text{2}}{\text{O}}_{\text{2}}$. The other carbon is converted to a ketone as it has two carbons attached to it.

Therefore, the products of the reaction are

Conclusion

The products of the ozonolysis reaction were determined on the basis of cleavage of the double bond and oxidation of the two carbons to carbonyl groups.

Interpretation Introduction

(e)

Interpretation:

The organic product of the given reaction is to be drawn.

Concept introduction:

Multiple bonds in alkenes and alkynes are cleaved when treated with osmium tetroxide and ${\text{H}}_{\text{2}}{\text{O}}_{\text{2}}$. Both carbons of the alkene or alkyne are oxidized in the process to carbonyl groups. ${\text{OsO}}_4$ is added across the multiple bonds in a way similar to the Diels-Alder reaction, a $[4+2]$ cycloaddition. This is followed by a hydrolysis to a vicinal diol. Treatment of the vicinal diol by ${\text{IO}}_4$ produces a periodate ester. The final step is a cycloelimination than cleaves the $\text{C}-\text{C}$ bond to produce two carbonyl groups. If one of these is an aldehyde, it is not oxidized further to a carboxylate group.

Answer to Problem 24.57P

The structures of the organic products of the given reaction are

Explanation of Solution

The given reaction is

Osmium tetroxide adds across the double bond. Hydrolysis of the adduct yields a $\text{cis-1, 2-diol}$ (vicinal diol). Treatment of this diol by ${\text{HIO}}_4$ cleaves the $\text{C}-\text{C}$ bond to produce two carbonyl compound, a ketone, and an aldehyde.

Therefore, the products of the reaction are

Conclusion

The products of the reaction were determined on the basis of addition of ${\text{OsO}}_4$ across the double bond followed by hydrolysis to vicinal diol, the formation of periodate ester and ocidation of the double-bonded carbons to carbonyl groups.

Interpretation Introduction

(f)

Interpretation:

The organic product of the given reaction is to be drawn.

Concept introduction:

Multiple bonds in alkenes and alkynes are cleaved when treated with hot, concentrated permanganate in a basic solution in an oxidative cleavage reaction. Both carbons of the alkene or alkyne are oxidized in the process to carbonyl groups or carbon dioxide. The final functional group that is formed depends on the reaction conditions. The permanganate ion is added across the multiple bonds in a way similar to the Diels-Alder reaction, a $[4+2]$ cycloaddition. This is followed by a $[4+2]$ cycloelimination that breaks the $\text{C}-\text{C}$ bond, eliminating ${\text{MnO}}_{\text{2}}$. The two carbons are converted to carbonyl groups in this step. If these carbons have two alkyl groups bonded to them, they are converted to ketone groups. If only one alkyl group is present, the carbon is converted to an aldehyde. Aldehyde groups are further oxidized to carboxylate group under the reaction conditions. This may be converted to a carboxylic acid by an acid workup. If there are no alkyl groups attached to the carbon, it is completely oxidized to carbon dioxide.

Answer to Problem 24.57P

The structures of the organic products of the given reaction are

Explanation of Solution

The given reaction is

Hot, concentrated permanganate (${\text{KMnO}}_4$) will cleave the double bond, oxidizing the two carbon atoms to carbonyl groups. Both carbon atoms are bonded to two other carbons, therefore, both are oxidized to ketones.

Therefore, the product of the reaction is

Conclusion

Hot concentrated permanganate in basic medium oxidized the double-bonded carbons of an alkene to carbonyl groups.