Textbook Question
In its open-chain form, D-mannose, an aldohexose found in orange peels, has the structure shown here. Coil mannose around and draw it in the cyclic hemiacetal ⍺ and β forms.
648
views
Ch.20 Carbohydrates
McMurry8th EditionFundamentals of GOBISBN: 9780134015187
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 Matter and Measurements27
- Ch.2 Atoms and the Periodic Table20
- Ch.3 Ionic Compounds8
- Ch.4 Molecular Compounds23
- Ch.5 Classification & Balancing of Chemical Reactions12
- Ch.6 Chemical Reactions: Mole and Mass Relationships28
- Ch.7 Chemical Reactions: Energy, Rate and Equilibrium64
- Ch.8 Gases, Liquids and Solids24
- Ch.9 Solutions52
- Ch.10 Acids and Bases25
- Ch.11 Nuclear Chemistry22
- Ch.12 Introduction to Organic Chemistry: Alkanes57
- Ch.13 Alkenes, Alkynes, and Aromatic Compounds47
- Ch.14 Some Compounds with Oxygen, Sulfur, or a Halogen50
- Ch.15 Aldehydes and Ketones45
- Ch.16 Amines42
- Ch.17 Carboxylic Acids and Their Derivatives57
- Ch.18 Amino Acids and Proteins82
- Ch.19 Enzymes and Vitamins63
- Ch.20 Carbohydrates44
- Ch.21 The Generation of Biochemical Energy65
- Ch.22 Carbohydrate Metabolism45
- Ch.23 Lipids42
- Ch.24 Lipid Metabolism33
- Ch.25 Protein and Amino Acid Metabolism24
- Ch.26 Nucleic Acids and Protein Synthesis45
Chapter 20, Problem 54
Treatment of an aldose with an oxidizing agent such as Tollens’ reagent yields a carboxylic acid. Gluconic acid, the product of glucose oxidation, is used as its magnesium salt for the treatment of magnesium deficiency. Draw the structure of gluconic acid.
Verified step by step guidance1
Understand the reaction: An aldose, such as glucose, reacts with an oxidizing agent like Tollens' reagent. This reaction oxidizes the aldehyde group (-CHO) at the top of the aldose to a carboxylic acid group (-COOH).
Identify the structure of glucose: Glucose is an aldose sugar with the molecular formula C₆H₁₂O₆. It has an aldehyde group at the top (C1) and hydroxyl groups (-OH) attached to the remaining carbon atoms in a specific stereochemical arrangement.
Determine the oxidation site: The aldehyde group (-CHO) at carbon 1 (C1) of glucose is the functional group that gets oxidized to a carboxylic acid (-COOH). The rest of the molecule remains unchanged.
Draw the structure of gluconic acid: Replace the aldehyde group (-CHO) at C1 of glucose with a carboxylic acid group (-COOH). The hydroxyl groups (-OH) on carbons 2 through 5 and the terminal -CH₂OH group at C6 remain in their original positions.
Verify the structure: Ensure that the resulting molecule has the correct functional groups and stereochemistry. The final structure of gluconic acid should have a carboxylic acid group at C1, hydroxyl groups on C2 through C5, and a -CH₂OH group at C6.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Aldose
An aldose is a type of monosaccharide (simple sugar) that contains an aldehyde group (-CHO) at one end of its carbon chain. This functional group is crucial for the reactivity of aldoses, allowing them to undergo oxidation reactions. Glucose, a common aldose, can be oxidized to form various products, including gluconic acid when treated with oxidizing agents.
Recommended video:
Guided course
0:39
Common Naming of Sugar Alcohols Concept 3
Oxidizing Agents
Oxidizing agents are substances that can accept electrons from another species, thereby causing oxidation. In the context of carbohydrates, agents like Tollens’ reagent can oxidize aldoses to their corresponding carboxylic acids. This reaction is significant in organic chemistry as it helps in identifying and characterizing sugars based on their reactivity.
Recommended video:
Guided course
1:49Alcohol Reactions: Oxidation Concept 1
Gluconic Acid
Gluconic acid is a carboxylic acid derived from the oxidation of glucose. It features a carboxyl group (-COOH) replacing the aldehyde group of glucose, resulting in a six-carbon chain with a functional group that imparts acidic properties. Gluconic acid and its salts, such as magnesium gluconate, are utilized in various applications, including dietary supplements for magnesium deficiency.
Recommended video:
Guided course
02:15Naming Acids
Related Practice
Textbook Question
Treatment of D-glucose with a reducing agent yields sorbitol, a substance used as a sugar substitute by people with diabetes. Draw the structure of sorbitol.
979
views
Textbook Question
Reduction of D-fructose with a reducing agent yields a mixture of D-sorbitol along with a second, isomeric product. What is the structure of the second product?
1026
views
Textbook Question
Oxidation of the aldehyde group of ribose yields a carboxylic acid. Draw the structure of ribonic acid.
637
views
Textbook Question
Look at the open-chain form of D-mannose and draw the two glycosidic products that you expect to obtain by reacting D-mannose with methanol.
1403
views
Textbook Question
Draw a disaccharide of two cyclic mannose molecules attached by an α-1,4 glycosidic linkage. Explain why the glycosidic products in Problem 20.58 are not reducing sugars, but the product in this problem is a reducing sugar.
602
views