Chapter 28, Problem 28.50P

Draw the products formed when D-altrose is treated with each reagent.

a. ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}\text{CHOH}$, $\text{HCl}$

b. ${\text{NaBH}}_{\text{4}}$, ${\text{CH}}_{\text{3}}\text{OH}$

c. ${\text{Br}}_{\text{2}}$, ${\text{H}}_{\text{2}}\text{O}$

d. ${\text{HNO}}_{\text{3}}$, ${\text{H}}_{\text{2}}\text{O}$

e. [1] ${\text{NH}}_{\text{2}}\text{OH}$, [2] ${\left({\text{CH}}_{\text{3}}\text{CO}\right)}_{\text{2}}\text{O}$, ${\text{NaOCOCH}}_{\text{3}}$ [3] ${\text{NaOCH}}_{\text{3}}$

f. [1] $\text{NaCN}$, $\text{HCl}$[2] ${\text{H}}_{\text{2}}$, $\text{Pd}-{\text{BaSO}}_{\text{4}}$ [3] ${\text{H}}_{\text{3}}{\text{O}}^{+}$

g. ${\text{Ag}}_{\text{2}}\text{O}$, ${\text{CH}}_3\text{I}$

h. ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$, mild ${\text{H}}^{+}$

Interpretation Introduction

(a)

Interpretation: The products formed by the treatment of D-altrose with ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}\text{CHOH}$, $\text{HCl}$ are to be drawn.

Concept introduction: The $\text{OH}$ groups of monosaccharides on reaction with alcohol in the presence of strong acid results in the formation of acetals. Acetals are the groups in which carbon atom is bonded to two $\text{OR}$ groups through single bonds. They are used as protecting groups for aldehyde and ketones.

Answer to Problem 28.50P

The products formed by the treatment of D-altrose with ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}\text{CHOH}$, $\text{HCl}$ are,

Figure 1

Explanation of Solution

The $\text{OH}$ groups of monosaccharides on reaction with alcohol in the presence of strong acid result in the formation of acetal. Acetals are the groups in which carbon atom is bonded to two $\text{OR}$ groups through single bonds. They are used as protecting groups for aldehyde and ketones.

The products formed by the treatment of D- altrose with ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}\text{CHOH}$, $\text{HCl}$ are shown below.

Figure 2

Conclusion

The products formed by the treatment of D-altrose with ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}\text{CHOH}$, $\text{HCl}$ are shown in Figure 1.

Interpretation Introduction

(b)

Interpretation: The products formed by the treatment of D-altrose with ${\text{NaBH}}_{\text{4}}$, ${\text{CH}}_{\text{3}}\text{OH}$ are to be drawn.

Concept introduction: The substitution reaction involves the replacement of one functional group by other functional group. In nucleophilic substitution an electron rich species attack the species that is deficient in electrons. The electrophile and the leaving group together form a substrate. The nucleophile attacks over the substrate and there occurs the removal of leaving group from the substrate.

Answer to Problem 28.50P

The product formed by the treatment of D-altrose with ${\text{NaBH}}_{\text{4}}$, ${\text{CH}}_{\text{3}}\text{OH}$ is,

Figure 3

Explanation of Solution

The product formed by the treatment of D-altrose with ${\text{NaBH}}_{\text{4}}$, ${\text{CH}}_{\text{3}}\text{OH}$ is shown below.

Figure 4

In the given reaction, sodium borohydride is used as a reducing agent. Sodium borohydride is used to for the reduction of carbonyl compounds to alcohols.

Conclusion

The product formed by the treatment of D-altrose with ${\text{NaBH}}_{\text{4}}$, ${\text{CH}}_{\text{3}}\text{OH}$ is shown in Figure 3.

Interpretation Introduction

(c)

Interpretation: The products formed by the treatment of D-altrose with ${\text{Br}}_{\text{2}}$, ${\text{H}}_{\text{2}}\text{O}$ are to be drawn.

Concept introduction: The aldehyde group of aldoses oxidizes to carboxyl group on treatment with ${\text{Br}}_{\text{2}}$, ${\text{H}}_2\text{O}$. The oxidation of aldoses leads to the formation of aldonic acid.

Answer to Problem 28.50P

The product formed by the treatment of D-altrose with ${\text{Br}}_{\text{2}}$, ${\text{H}}_{\text{2}}\text{O}$ is,

Figure 5

Explanation of Solution

The oxidation of aldehyde group of aldoses leads to the formation of aldonic acid, in which the terminal carbon atoms are substituted by carboxyl group and alcoholic group. The product formed by the treatment of D-altrose with ${\text{Br}}_{\text{2}}$, ${\text{H}}_{\text{2}}\text{O}$ is shown below.

Figure 6

Conclusion

The product formed by the treatment of D-altrose with ${\text{Br}}_{\text{2}}$, ${\text{H}}_{\text{2}}\text{O}$ is shown in Figure 5.

Interpretation Introduction

(d)

Interpretation: The products formed by the treatment of D-altrose with ${\text{HNO}}_{\text{3}}$, ${\text{H}}_{\text{2}}\text{O}$ are to be drawn.

Concept introduction: The aldehyde group and primary alcohol of aldoses oxidizes to carboxyl groups on treatment with warm ${\text{HNO}}_{\text{3}}$. The oxidation of aldoses leads to the formation of aldaric acid.

Answer to Problem 28.50P

The product formed by the treatment of D-altrose with ${\text{HNO}}_{\text{3}}$, ${\text{H}}_{\text{2}}\text{O}$ is,

Figure 7

Explanation of Solution

The oxidation of aldehyde group and primary alcohol of aldoses leads to the formation of aldaric acid, in which the terminal carbon atoms are substituted by carboxyl groups. The product formed by the treatment of D-altrose with ${\text{HNO}}_{\text{3}}$, ${\text{H}}_{\text{2}}\text{O}$ is shown below.

Figure 8

Conclusion

The product formed by the treatment of D-altrose with ${\text{HNO}}_{\text{3}}$, ${\text{H}}_{\text{2}}\text{O}$ is shown in Figure 7.

Interpretation Introduction

(e)

Interpretation: The products formed by the treatment of D-altrose with [1] ${\text{NH}}_{\text{2}}\text{OH}$, [2] ${\left({\text{CH}}_{\text{3}}\text{CO}\right)}_{\text{2}}\text{O}$, ${\text{NaOCOCH}}_{\text{3}}$ [3] ${\text{NaOCH}}_{\text{3}}$ are to be drawn.

Concept introduction:

Answer to Problem 28.50P

The product formed by the treatment of D-altrose with [1] ${\text{NH}}_{\text{2}}\text{OH}$, [2] ${\left({\text{CH}}_{\text{3}}\text{CO}\right)}_{\text{2}}\text{O}$, ${\text{NaOCOCH}}_{\text{3}}$ [3] ${\text{NaOCH}}_{\text{3}}$ are,

Figure 9

Explanation of Solution

The reaction of D-altrose with hydroxylamine results in the formation of oxime. The second step is the dehydration of oxime to nitriles. The reaction of nitrile with ${\text{NaOCH}}_{\text{3}}$ results in the formation of aldehyde by the loss of $\text{HCN}$.

The product formed by the treatment of D-altrose with [1] ${\text{NH}}_{\text{2}}\text{OH}$, [2] ${\left({\text{CH}}_{\text{3}}\text{CO}\right)}_{\text{2}}\text{O}$, ${\text{NaOCOCH}}_{\text{3}}$ [3] ${\text{NaOCH}}_{\text{3}}$ are shown below.

Figure 10

Conclusion

The product formed by the treatment of D-altrose with [1] ${\text{NH}}_{\text{2}}\text{OH}$, [2] ${\left({\text{CH}}_{\text{3}}\text{CO}\right)}_{\text{2}}\text{O}$, ${\text{NaOCOCH}}_{\text{3}}$ [3] ${\text{NaOCH}}_{\text{3}}$ are shown in Figure 9.

Interpretation Introduction

(f)

Interpretation: The products formed by the treatment of D-altrose with [1] $\text{NaCN}$, $\text{HCl}$[2] ${\text{H}}_{\text{2}}$, $\text{Pd}-{\text{BaSO}}_{\text{4}}$ [3] ${\text{H}}_{\text{3}}{\text{O}}^{+}$ are to be drawn.

Concept introduction:

Answer to Problem 28.50P

The products formed by the treatment of D-altrose with [1] $\text{NaCN}$, $\text{HCl}$[2] ${\text{H}}_{\text{2}}$, $\text{Pd}-{\text{BaSO}}_{\text{4}}$ [3] ${\text{H}}_{\text{3}}{\text{O}}^{+}$ are,

Figure 11

Explanation of Solution

The products formed by the treatment of D-altrose with [1] $\text{NaCN}$, $\text{HCl}$[2] ${\text{H}}_{\text{2}}$, $\text{Pd}-{\text{BaSO}}_{\text{4}}$ [3] ${\text{H}}_{\text{3}}{\text{O}}^{+}$ are shown below.

Figure 12

Conclusion

The products formed by the treatment of D-altrose with [1] $\text{NaCN}$, $\text{HCl}$[2] ${\text{H}}_{\text{2}}$, $\text{Pd}-{\text{BaSO}}_{\text{4}}$ [3] ${\text{H}}_{\text{3}}{\text{O}}^{+}$ are shown in Figure 11.

Interpretation Introduction

(g)

Interpretation: The products formed by the treatment of D-altrose with ${\text{Ag}}_{\text{2}}\text{O}$, ${\text{CH}}_3\text{I}$ are to be drawn.

Concept introduction: The $\text{OH}$ groups of monosaccharides on reaction with base and an alkyl halide convert into ether. A single product is formed during this reaction because the configuration of all substituents in the starting material is retained.

Answer to Problem 28.50P

The products formed by the treatment of D-altrose with ${\text{Ag}}_{\text{2}}\text{O}$, ${\text{CH}}_3\text{I}$ are,

Figure 13

Explanation of Solution

The $\text{OH}$ groups of monosaccharides on reaction with base and an alkyl halide convert into ether. A single product is formed during this reaction because the configuration of all substituents in the starting material is retained. The products formed by the treatment of D- altrose with ${\text{Ag}}_{\text{2}}\text{O}$, ${\text{CH}}_3\text{I}$ are shown below.

Figure 14

Conclusion

The products formed by the treatment of D-altrose with ${\text{Ag}}_{\text{2}}\text{O}$, ${\text{CH}}_3\text{I}$ are shown in Figure 13.

Interpretation Introduction

(h)

Interpretation: The products formed by the treatment of D-altrose with ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$, mild ${\text{H}}^{+}$ are to be drawn.

Concept introduction: The $\text{OH}$ groups of monosaccharides on reaction with amine in the presence of mild acid results in the formation of two anomers of glycoside.

Answer to Problem 28.50P

The products formed by the treatment of D-altrose with ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$, mild ${\text{H}}^{+}$ are,

Figure 15

Explanation of Solution

The $\text{OH}$ groups of monosaccharides on reaction with base and an alkyl halide convert into ether. The products formed by the treatment of D- altrose with ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$, mild ${\text{H}}^{+}$ are shown below.

Figure 16

Conclusion

The products formed by the treatment of D-altrose with ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$, mild ${\text{H}}^{+}$ are shown in Figure 15.