The Kiliani–Fischer reaction for the synthesis of epimeric aldoses is to be outlined and Fischer projection of D − ( − ) − Arabinose and D − ( − ) − Ribose is to be represented on the basis of given information. Concept introduction: 舧 A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen-oxygen atom ratio of 2:1 舧 HNO 3 is an oxidizing agent. 舧 Carbohydrates are oxidized by HNO 3 to give aldaric acid as a product. 舧 Aldaric acids are carbohydrates having two carboxylic acids. They are formed due to oxidation reaction of aldoses with dilute HNO 3 and their general reaction can be represented as: 舧 The molecules that are nonsuperimposable or not identical with their mirror images are known as chiral molecules. 舧 A pair of two mirror images that are nonidentical is known as enantiomers, which are optically active. 舧 The stereoisomers that are nonsuperimposable on each other and not mirror images of each other are known as diastereomers. 舧 The achiral compounds in which plane of symmetry is present internally and consists of chiral centres are known as meso compounds, but they are optically inactive. 舧 Compounds that have a plane of symmetry tend to exist in meso forms. A meso form arises when the two stereoisomers produce superimposable images, and hence, compounds having meso forms are optically inactive. 舧 The Kiliani-Fischer reaction is used for increasing the number of carbon atoms of the respective aldoses, thereby, lengthening the carbon chain of the compound. It is an effective and economic process for synthesizing monosaccharides through the hydrolysis of a cyanohydrin. Thus, it lengthens the carbon chain of the aldose by one carbon atom. It is used to produce epimers of higher aldoses from a lower aldose, that is, a single aldose produces a mixture of two diastereomeric sugars called epimers.

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Definition Definition Class of organic compounds that contain a carboxyl group ( - COOH ) and has a general formula R - COOH or R - CO 2 H , where R refers to the alkyl, alkenyl, aryl, or other groups. They can undergo different chemical reactions, such as acid-base reactions, esterification, and oxidation. These are essential components of living organisms, playing important roles in metabolic processes, signaling, and as pharmaceuticals.

Chapter 22, Problem 14PP

Interpretation Introduction

Interpretation:

The Kiliani–Fischer reaction for the synthesis of epimeric aldoses is to be outlined and Fischer projection of D−(−)−Arabinose and D−(−)−Ribose is to be represented on the basis of given information.

Concept introduction:

舧 A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen-oxygen atom ratio of 2:1

舧 HNO3 is an oxidizing agent.

舧 Carbohydrates are oxidized by HNO3 to give aldaric acid as a product.

舧 Aldaric acids are carbohydrates having two carboxylic acids. They are formed due to oxidation reaction of aldoses with dilute HNO3 and their general reaction can be represented as:

舧 The molecules that are nonsuperimposable or not identical with their mirror images are known as chiral molecules.

舧 A pair of two mirror images that are nonidentical is known as enantiomers, which are optically active.

舧 The stereoisomers that are nonsuperimposable on each other and not mirror images of each other are known as diastereomers.

舧 The achiral compounds in which plane of symmetry is present internally and consists of chiral centres are known as meso compounds, but they are optically inactive.

舧 Compounds that have a plane of symmetry tend to exist in meso forms. A meso form arises when the two stereoisomers produce superimposable images, and hence, compounds having meso forms are optically inactive.

舧 The Kiliani-Fischer reaction is used for increasing the number of carbon atoms of the respective aldoses, thereby, lengthening the carbon chain of the compound. It is an effective and economic process for synthesizing monosaccharides through the hydrolysis of a cyanohydrin. Thus, it lengthens the carbon chain of the aldose by one carbon atom. It is used to produce epimers of higher aldoses from a lower aldose, that is, a single aldose produces a mixture of two diastereomeric sugars called epimers.

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An optically active D-aldopentose (A) produced an optically inactive alditol (B) upon treatment with H2/Pt. When the aldopentose (A) was subjected to a Ruff degradation, D-aldotetrose (C) was generated. The aldotetrose (C) gave an optically active aldaric acid (D) upon oxidation with HNO3. D-aldopentose (A) can be prepared from D-threose by a Killani Fischer synthesis. Propose structure of A through D.

Which of the following are reducing sugars? Comment on the common name sucrosefor table sugar.(a) methyl a-d-galactopyranoside (b) b-l-idopyranose (an aldohexose)(c) a-d-allopyranose (d) ethyl b-d-ribofuranoside

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Answer 2

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Definition Definition Class of organic compounds that contain a carboxyl group ( - COOH ) and has a general formula R - COOH or R - CO 2 H , where R refers to the alkyl, alkenyl, aryl, or other groups. They can undergo different chemical reactions, such as acid-base reactions, esterification, and oxidation. These are essential components of living organisms, playing important roles in metabolic processes, signaling, and as pharmaceuticals.

Chapter 22, Problem 14PP

Interpretation Introduction

Interpretation:

The Kiliani–Fischer reaction for the synthesis of epimeric aldoses is to be outlined and Fischer projection of D−(−)−Arabinose and D−(−)−Ribose is to be represented on the basis of given information.

Concept introduction:

舧 A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen-oxygen atom ratio of 2:1

舧 HNO3 is an oxidizing agent.

舧 Carbohydrates are oxidized by HNO3 to give aldaric acid as a product.

舧 Aldaric acids are carbohydrates having two carboxylic acids. They are formed due to oxidation reaction of aldoses with dilute HNO3 and their general reaction can be represented as:

舧 The molecules that are nonsuperimposable or not identical with their mirror images are known as chiral molecules.

舧 A pair of two mirror images that are nonidentical is known as enantiomers, which are optically active.

舧 The stereoisomers that are nonsuperimposable on each other and not mirror images of each other are known as diastereomers.

舧 The achiral compounds in which plane of symmetry is present internally and consists of chiral centres are known as meso compounds, but they are optically inactive.

舧 Compounds that have a plane of symmetry tend to exist in meso forms. A meso form arises when the two stereoisomers produce superimposable images, and hence, compounds having meso forms are optically inactive.

舧 The Kiliani-Fischer reaction is used for increasing the number of carbon atoms of the respective aldoses, thereby, lengthening the carbon chain of the compound. It is an effective and economic process for synthesizing monosaccharides through the hydrolysis of a cyanohydrin. Thus, it lengthens the carbon chain of the aldose by one carbon atom. It is used to produce epimers of higher aldoses from a lower aldose, that is, a single aldose produces a mixture of two diastereomeric sugars called epimers.

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Answer 3

Question

Definition Definition Class of organic compounds that contain a carboxyl group ( - COOH ) and has a general formula R - COOH or R - CO 2 H , where R refers to the alkyl, alkenyl, aryl, or other groups. They can undergo different chemical reactions, such as acid-base reactions, esterification, and oxidation. These are essential components of living organisms, playing important roles in metabolic processes, signaling, and as pharmaceuticals.

Chapter 22, Problem 14PP

Interpretation Introduction

Interpretation:

The Kiliani–Fischer reaction for the synthesis of epimeric aldoses is to be outlined and Fischer projection of D−(−)−Arabinose and D−(−)−Ribose is to be represented on the basis of given information.

Concept introduction:

舧 A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen-oxygen atom ratio of 2:1

舧 HNO3 is an oxidizing agent.

舧 Carbohydrates are oxidized by HNO3 to give aldaric acid as a product.

舧 Aldaric acids are carbohydrates having two carboxylic acids. They are formed due to oxidation reaction of aldoses with dilute HNO3 and their general reaction can be represented as:

舧 The molecules that are nonsuperimposable or not identical with their mirror images are known as chiral molecules.

舧 A pair of two mirror images that are nonidentical is known as enantiomers, which are optically active.

舧 The stereoisomers that are nonsuperimposable on each other and not mirror images of each other are known as diastereomers.

舧 The achiral compounds in which plane of symmetry is present internally and consists of chiral centres are known as meso compounds, but they are optically inactive.

舧 Compounds that have a plane of symmetry tend to exist in meso forms. A meso form arises when the two stereoisomers produce superimposable images, and hence, compounds having meso forms are optically inactive.

舧 The Kiliani-Fischer reaction is used for increasing the number of carbon atoms of the respective aldoses, thereby, lengthening the carbon chain of the compound. It is an effective and economic process for synthesizing monosaccharides through the hydrolysis of a cyanohydrin. Thus, it lengthens the carbon chain of the aldose by one carbon atom. It is used to produce epimers of higher aldoses from a lower aldose, that is, a single aldose produces a mixture of two diastereomeric sugars called epimers.

Expert Solution & Answer

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Check out a sample textbook solution

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Answer 4

Question

Definition Definition Class of organic compounds that contain a carboxyl group ( - COOH ) and has a general formula R - COOH or R - CO 2 H , where R refers to the alkyl, alkenyl, aryl, or other groups. They can undergo different chemical reactions, such as acid-base reactions, esterification, and oxidation. These are essential components of living organisms, playing important roles in metabolic processes, signaling, and as pharmaceuticals.

Chapter 22, Problem 14PP

Interpretation Introduction