Textbook Question
Classify each of the following monosaccharides as an aldopentose, ketopentose, aldohexose, or ketohexose:
a. Psicose is present in low amounts in foods.
Ch.13 Carbohydrates
Timberlake13th EditionChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9780134421353
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Table of contents
- Ch.1 Chemistry in Our Lives11
- Ch.2 Chemistry and Measurements80
- Ch.3 Matter and Energy54
- Ch.4 Atoms and Elements51
- Ch.5 Nuclear Chemistry42
- Ch.6 Ionic and Molecular Compounds57
- Ch.7 Chemical Quantities and Reactions41
- Ch.8 Gases29
- Ch.9 Solutions51
- Ch.10 Acids and Bases and Equilibrium65
- Ch.11 Introduction to Organic Chemistry: Hydrocarbons78
- Ch.12 Alcohols, Thiols, Ethers, Aldehydes, and Ketones83
- Ch.13 Carbohydrates54
- Ch.14 Carboxylic Acids, Esters, Amines, and Amides90
- Ch.15 Lipids61
- Ch.16 Amino Acids, Proteins, and Enzymes84
- Ch.17 Nucleic Acids and Protein Synthesis83
- Ch.18 Metabolic Pathways and ATP Production67
Timberlake13th EditionChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9780134421353Not the one you use?Change textbook
Chapter 13, Problem 13a
Draw the Fischer projection for each of the following wedge–dash structures:
a. 
Verified step by step guidance1
Understand the Fischer projection: A Fischer projection is a two-dimensional representation of a molecule where the carbon chain is drawn vertically, and horizontal lines represent bonds projecting out of the plane (toward the viewer), while vertical lines represent bonds projecting behind the plane (away from the viewer).
Identify the chiral carbon centers in the wedge–dash structure. Chiral carbons are carbon atoms bonded to four different groups. These will be the focus of the Fischer projection.
Orient the molecule so that the longest carbon chain is vertical, with the most oxidized carbon (e.g., a carbonyl group or the carbon attached to the most electronegative atom) at the top. This is the standard orientation for Fischer projections.
Convert the wedge–dash notation to the Fischer projection: Bonds shown as wedges (projecting out of the plane) should be drawn as horizontal lines in the Fischer projection, while bonds shown as dashes (projecting behind the plane) should be drawn as vertical lines.
Double-check the stereochemistry: Ensure that the relative positions of the substituents around each chiral carbon in the Fischer projection match the original wedge–dash structure. This ensures the correct 3D arrangement is preserved in the 2D representation.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Fischer Projection
The Fischer projection is a two-dimensional representation of a three-dimensional organic molecule, particularly useful for depicting carbohydrates and amino acids. In this format, vertical lines represent bonds that extend behind the plane of the paper, while horizontal lines represent bonds that extend in front. This method simplifies the visualization of stereochemistry, allowing for easy identification of chiral centers and their configurations.
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Fischer Projections Example 1
Wedge-Dash Notation
Wedge-dash notation is a way to represent the three-dimensional arrangement of atoms in a molecule. In this notation, solid wedges indicate bonds that project out of the plane of the paper towards the viewer, while dashed lines represent bonds that extend behind the plane. This visual tool helps chemists understand the spatial orientation of substituents around chiral centers, which is crucial for determining the molecule's stereochemistry.
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01:41Scientific Notation
Stereochemistry
Stereochemistry is the study of the spatial arrangement of atoms in molecules and how this arrangement affects their chemical properties and reactions. It is particularly important in organic chemistry, where the orientation of functional groups can influence a compound's reactivity and interactions. Understanding stereochemistry is essential for accurately converting between different representations of molecules, such as wedge-dash structures and Fischer projections.
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1:30D vs L Enantiomers Concept 1
Related Practice
Textbook Question
What functional groups are found in all monosaccharides?
Textbook Question
What are the functional groups and number of carbons in a ketopentose?
Textbook Question
Draw the Fischer projection for each of the following wedge–dash structures:
a.
Textbook Question
Indicate whether each pair of Fischer projections represents enantiomers or identical structures.
a.
Textbook Question
Indicate whether each pair of Fischer projections represents enantiomers or identical structures.
b.