Chapter 20, Problem 20.47AP

Interpretation Introduction

(a)

Interpretation:

Synthesis of $2\text{-pentanol}$ from propanoic acid using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, multiple number of steps undergoes using multiple reagents.

Answer to Problem 20.47AP

Synthesis of $2\text{-pentanol}$ from propanoic acid using appropriate reagents is shown below.

Explanation of Solution

The synthesis of $2\text{-pentanol}$ from propanoic acid is done using multiple steps shown below.

Figure 1

The total number of steps in the synthesis are five. In the first step propanoic acid is converted into acid chloride which is converted into ketone using Grignard’s reagent.

The ketone $\text{2-butanone}$ thus formed is brominated at the alpha position. Then the brominated product undergoes dehydrohalogenation in the presence of alcoholic $\text{KOH}$ to give $\alpha ,\beta \text{-}$ unsaturated ketone. The Michael addition of Gilman’s reagent on the $\alpha ,\beta \text{-}$ unsaturated ketone $\text{3-buten-2-one}$ takes place to give the required product $2\text{-pentanol}$.

Conclusion

Synthesis of $2\text{-pentanol}$ from propanoic acid using appropriate reagents is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation:

Synthesis of the given compound from allyl alcohol using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of the given compound from allyl alcohol using appropriate reagents is shown below.

Explanation of Solution

The given compound to be synthesized is shown below.

Figure 2

The synthesis of the given compound from allyl alcohol is done using multiple steps shown below.

Figure 3

The allyl alcohol, $\text{prop-2-en-1-ol}$ is reduced first of all to the $\text{propan-1-ol}$ which is then oxidized to carboxylic acid propionic acid. The propionic acid then formed reacts with the allyl alcohol to give the required product.

Conclusion

Synthesis of the given compound from allyl alcohol using appropriate reagents is shown in Figure 3.

Interpretation Introduction

(c)

Interpretation:

Synthesis of $\text{2-methylheptane}$ from pentanoic acid using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of $\text{2-methylheptane}$ from pentanoic acid using appropriate reagents is shown below.

Explanation of Solution

The synthesis of $\text{2-methylheptane}$ from pentanoic acid using appropriate reagents is done using multiple steps shown below.

Figure 4

The conversion of pentanoic acid to acid chloride is done by using thionyl chloride. The acid chloride thus produced is reacted with DIBAH at $-78°\text{C}$ to give pentanal. The pentanal thus produced with a Grignard reagent to give $\text{2-methyl-3-heptanol}$ which is then dehydrated in the presence of concentrated acid to give an alkene $\text{2-methyl-2-heptene}$. The $\text{2-methyl-2-heptene}$ is then reduced using catalytic hydrogenation to give the required product $\text{2-methylheptane}$.

Conclusion

Synthesis of $\text{2-methylheptane}$ from pentanoic acid using appropriate reagents is shown in Figure 4.

Interpretation Introduction

(d)

Interpretation:

Synthesis of $m\text{-nitrobenzoic}\text{acid}$ from toluene using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of $m\text{-nitrobenzoic}\text{acid}$ from toluene using appropriate reagents is shown below.

Explanation of Solution

The synthesis of $m\text{-nitrobenzoic}\text{acid}$ from toluene using appropriate reagents is done using multiple steps shown below.

Figure 5

Toluene is first oxidized using potassium permanganate to give benzoic acid. A carboxylic acid group is a meta-directing group. The benzoic acid is then nitrated to give $m\text{-nitrobenzoic}\text{acid}$.

Conclusion

Synthesis of $m\text{-nitrobenzoic}\text{acid}$ from toluene using appropriate reagents is shown in Figure 5.

Interpretation Introduction

(e)

Interpretation:

Synthesis of ${\text{PhCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{Ph}$ from benzoic acid using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of ${\text{PhCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{Ph}$ from benzoic acid using appropriate reagents is shown below.

Explanation of Solution

The synthesis of ${\text{PhCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{Ph}$ from benzoic acid using appropriate reagents is done using multiple steps shown below.

Figure 6

Benzoic acid is converted into benzoyl chloride in the first step which is then reacted with Grignard’s reagent to give an appropriate ketone which on Clemmensen reduction gives the required product ${\text{PhCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{Ph}$.

Conclusion

Synthesis of ${\text{PhCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{Ph}$ from benzoic acid using appropriate reagents is shown in Figure 6.

Interpretation Introduction

(f)

Interpretation:

Synthesis of given $\text{γ-lactone}$ from $\text{4-oxopentanoic}\text{acid}$ using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of given $\text{γ-lactone}$ from $\text{4-oxopentanoic}\text{acid}$ using appropriate reagents is shown below.

Explanation of Solution

The synthesized compound is $\text{γ-lactone}$ is shown below.

Figure 7

Synthesis of given $\text{γ-lactone}$ from $\text{4-oxopentanoic}\text{acid}$ using appropriate reagents is done using multiple steps shown below.

Figure 8

The $\text{4-oxopentanoic}\text{acid}$ is first of selectively reduced using sodium borohydride to give $\text{4-hydroxypentanoic}\text{acid}$ a $\text{γ-hydroxy}\text{acid}$. The $\text{4-hydroxypentanoic}\text{acid}$ is converted into required $\text{γ-lactone}$ in the presence of acid.

Conclusion

Synthesis of given $\text{γ-lactone}$ from $\text{4-oxopentanoic}\text{acid}$ using appropriate reagents is shown in Figure 8.

Interpretation Introduction

(g)

Interpretation:

Synthesis of given dicarboxylic acid from norbornene using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of given dicarboxylic acid from norbornene using appropriate reagents is shown below.

Explanation of Solution

The given dicarboxylic acid is shown below.

Figure 9

Synthesis of given dicarboxylic acid from norbornene using appropriate reagents is done in a single step shown below.

Figure 10

The conversion of norbornene into the required dicarboxylic acid is done in a single reaction. The ozonolysis of norbornene with oxidative work gives the required product.

Conclusion

Synthesis of given dicarboxylic acid from norbornene using appropriate reagents is shown in Figure 10.

Interpretation Introduction

(h)

Interpretation:

Synthesis of $\text{5-oxohexanoic}\text{acid}$ from $\text{5-bromo-2-pentanone}$ using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of $\text{5-oxohexanoic}\text{acid}$ from $\text{5-bromo-2-pentanone}$ using appropriate reagents is shown below.

Explanation of Solution

Synthesis of $\text{5-oxohexanoic}\text{acid}$ from $\text{5-bromo-2-pentanone}$ using appropriate reagents is done in multiple steps shown below.

Figure 11

The compound, $\text{5-bromo-2-pentanone}$ is first of all reacted with ethylene glycol in the presence of acid to protect the carbonyl group. The bromide group is then substituted in the second by cyanide ion. The resultant product is then hydrolyzed to give the required product $\text{5-oxohexanoic}\text{acid}$.

Conclusion

Synthesis of $\text{5-oxohexanoic}\text{acid}$ from $\text{5-bromo-2-pentanone}$ using appropriate reagents is shown in Figure 11.

Interpretation Introduction

(i)

Interpretation:

Synthesis of $cis\text{-cinnamic}\text{acid}$ from $\text{Ph}-\text{C}\equiv \text{C}-\text{H}$ using appropriate reagents is to be stated.

Concept introduction:

Synthesis is the process of conversion of one compound into another using reagents. For the conversion of one compound into another, the multiple numbers of steps undergo using multiple reagents.

Answer to Problem 20.47AP

Synthesis of $cis\text{-cinnamic}\text{acid}$ from $\text{Ph}-\text{C}\equiv \text{C}-\text{H}$ using appropriate reagents is shown below.

Explanation of Solution

Synthesis of $cis\text{-cinnamic}\text{acid}$ from $\text{Ph}-\text{C}\equiv \text{C}-\text{H}$ using appropriate reagents is done in multiple steps shown below.

Figure 12

The compound, $\text{Ph}-\text{C}\equiv \text{C}-\text{H}$ is first of all reacted with ${\text{NaNH}}_{\text{2}}$ and ${\text{CO}}_{\text{2}}$ to give $\text{3-phenylpropiolic}\text{acid}$. The role of ${\text{NaNH}}_{\text{2}}$ is to abstract the acidic proton to generate a carbanion which reacts with ${\text{CO}}_{\text{2}}$ to give carboxylic acid. The $\text{3-phenylpropiolic}\text{acid}$ is then reacted with Lindlar’s catalyst which reduces the alkene functional group into cis-alkene and thus gives the required product $cis\text{-cinnamic}\text{acid}$.

Conclusion

Synthesis of $cis\text{-cinnamic}\text{acid}$ from $\text{Ph}-\text{C}\equiv \text{C}-\text{H}$ using appropriate reagents is Figure 12.