Chapter 12, Problem 12.46P

What alkene is needed to synthesize each $1,2\text{-<x-custom-btb-me data-me-id="2537" class="microExplainerHighlight">diol</x-custom-btb-me>}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}$ in ${\text{H}}_{\text{2}}\text{O}$;

or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{OH}}^{-}$ in ${\text{H}}_{\text{2}}\text{O}$?

a. b. c.

Interpretation Introduction

(a)

Interpretation: The alkene needed to synthesize the given $1,2\text{-diol}$ using $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is to be predicted.

Concept introduction: Addition of two hydroxyl groups on double bond to form $1,2\text{-diol}$ is known as dihydroxylation. In presence of ${\text{OsO}}_{\text{4}}$, syn dihydroxylation takes place. In this reaction, two hydroxyl groups are added on the same side of the double bond.

In the presence of peroxide, alkene is oxidized to epoxide. This is known as epoxidation. This is a syn addition. The weak pi bond of alkene and weak $\text{O}-\text{O}$ bond of peroxide are broken and two new $\text{C}-\text{O}$ bonds are formed. Breaking of bonds and formation of bonds takes place in single step. In opening of the epoxide ring the nucleophile attacks from the backside of the $\text{C}-\text{O}$ bond.

Answer to Problem 12.46P

The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is shown in Figure 1 and Figure 3.

Explanation of Solution

$\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$

In presence of ${\text{OsO}}_{\text{4}}$ followed by hydrolysis with ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$, $1,2\text{-diol}$ is formed. This is syn dihydroxylation. The required alkene is,

Figure 1

The corresponding chemical reaction is given below.

Figure 2

$\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$

In presence of ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$, alkene is oxidized to epoxide. Epoxidation is followed by ring opening with ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$. This is anti dihydroxylation. The required alkene is,

Figure 3

The corresponding chemical reaction is given below.

Figure 4

Conclusion

The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is shown in Figure 1 and Figure 3.

Interpretation Introduction

(b)

Interpretation: The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[1\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is to be predicted.

Concept introduction: Addition of two hydroxyl groups on double bond to form $1,2\text{-diol}$ is known as dihydroxylation. In presence of ${\text{OsO}}_{\text{4}}$, syn dihydroxylation takes place. In this reaction, two hydroxyl groups are added on the same side of the double bond.

In the presence of peroxide, alkene is oxidized to epoxide. This is known as epoxidation. This is a syn addition. The weak pi bond of alkene and weak $\text{O}-\text{O}$ bond of peroxide are broken and two new $\text{C}-\text{O}$ bonds are formed. Breaking of bonds and formation of bonds takes place in single step. In opening of the epoxide ring the nucleophile attacks from the backside of the $\text{C}-\text{O}$ bond.

Answer to Problem 12.46P

The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is shown in Figure 5 and Figure 7.

Explanation of Solution

$\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$

In presence of ${\text{OsO}}_{\text{4}}$ followed by hydrolysis with ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$, $1,2\text{-diol}$ is formed. This is syn dihydroxylation. The required alkene is,

Figure 5

The chemical reaction is given below.

Figure 6

$\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$

In presence of ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$, alkene is oxidized to epoxide. Epoxidation is followed by ring opening with ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$. This is anti dihydroxylation. The required alkene is,

Figure 7

The chemical reaction is given below.

Figure 8

Conclusion

The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is shown in Figure 5 and Figure 7.

Interpretation Introduction

(c)

Interpretation: The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[1\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is to be predicted.

Concept introduction: Addition of two hydroxyl groups on double bond to form $1,2\text{-diol}$ is known as dihydroxylation. In presence of ${\text{OsO}}_{\text{4}}$, syn dihydroxylation takes place. In this reaction two hydroxyl groups are added on the same side of the double bond.

In the presence of peroxide, alkene is oxidized to epoxide. This is known as epoxidation. This is a syn addition. The weak pi bond of alkene and weak $\text{O}-\text{O}$ bond of peroxide are broken and two new $\text{C}-\text{O}$ bonds are formed. Breaking of bonds and formation of bonds takes place in single step. In opening of the epoxide ring the nucleophile attacks from the backside of the $\text{C}-\text{O}$ bond.

Answer to Problem 12.46P

The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is shown in Figure 10 and Figure 12.

Explanation of Solution

The given alkene is,

Figure 9

This is a staggered conformation in which two hydroxyl groups are anti to each other.

$\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$

In presence of ${\text{OsO}}_{\text{4}}$ followed by hydrolysis with ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$, $1,2\text{-diol}$ is formed. This is syn dihydroxylation. The required alkene is,

Figure 10

The chemical reaction is given below.

Figure 11

$\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$

In presence of ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$, alkene is oxidized to epoxide. Epoxidation is followed by ring opening with ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$. This is anti dihydroxylation. The required alkene is,

Figure 12

The chemical reaction is given below.

Figure 13

Conclusion

The alkene needed to synthesize the given $1,2\text{-diol}$ using the $\left[1\right]$ ${\text{OsO}}_{\text{4}}$ followed by ${\text{NaHSO}}_{\text{3}}+{\text{H}}_{\text{2}}\text{O}$; or $\left[2\right]$ ${\text{CH}}_{\text{3}}{\text{CO}}_{\text{3}}\text{H}$ followed by ${\text{H}}_{\text{2}}\text{O},{\text{OH}}^{-}$ is shown in Figure 10 and Figure 12.