Concept explainers
(a)
Interpretation: The aldoses formed when D-threose is subjected to the Kiliani–Fischer synthesis are to be predicted.
Concept introduction: Kiliani–Fischer synthesis is a method which is used for the elongation of the carbon chains in aldose. In this method, the aldose chain is elongated by the formation of new stereogenic centre at
(b)
Interpretation: The aldoses formed when D-ribose is subjected to the Kiliani–Fischer synthesis are to be predicted.
Concept introduction: Kiliani–Fischer synthesis is a method which is used for the elongation of the carbon chains in aldose. In this method, the aldose chain is elongated by the formation of new stereogenic centre at
(c)
Interpretation: The aldoses formed when D-galactose is subjected to the Kiliani–Fischer synthesis are to be predicted.
Concept introduction: Kiliani–Fischer synthesis is a method which is used for the elongation of the carbon chains in aldose. In this method, the aldose chain is elongated by the formation of new stereogenic centre at
Want to see the full answer?
Check out a sample textbook solutionChapter 26 Solutions
Connect Online Access 1-Semester for Organic Chemistry
- (d) Draw the structure of the expected product when monosaccharide B undergo mutarotation upon dissolving in water in the presence of Tollens reagent (AGNO3, NHẠOH). он OH O. OH OH OH monosaccharide Barrow_forwardA D-aldopentose A is reduced to an optically active alditol. Upon Kiliani–Fischer synthesis, A is converted to two D-aldohexoses, B and C. B is oxidized to an optically inactive aldaric acid. C is oxidized to an optically active aldaric acid. What are the structures of A–C?arrow_forwardWhich D-aldopentoses are reduced to optically inactive alditols using NaBH4, CH3OH?arrow_forward
- The anticoagulant heparin is a polysaccharide that contains alternating residues of -D- glucuronic acid-6- sulfate and N-sulfo-D-glucosamine-6sulfate connected by (1 B 4)- glycosidic linkages. Draw a part of heparin that shows one each of the two residues.arrow_forward1. Draw Haworth projections of B-D-arabinofuranose and a-L-mannopyranose. 2. Consider the structure of the disaccharide drawn at right: НО `CH2 В ОН (a) Give the names and D/L designation for the two monosaccharides linked together. H,C-O OHO „OH OH А: НО НО A В: ОН (b) In the structure, circle the anomeric carbon of each saccharide. (c) Is each saccharide present in its a or ß anomer? Specify both A and B (d) Would this disaccharide undergo mutarotation? Why or why not? (e) Would this disaccharide react with Tollens and/or Benedicts reagent? Why or why not? (f) There are two reasons this is very unlikely to be a naturally occurring disaccharide. What about its structure suggests this is true? Give both reasons.arrow_forwardA D-aldopentose A is oxidized to an optically inactive aldaric acid with HNO3. A is formed by the Kiliani–Fischer synthesis of a D-aldotetrose B, which is also oxidized to an optically inactive aldaric acid with HNO3. What are the structures of A and B?arrow_forward
- Aldohexoses A and B are formed from aldopentose C via a Kiliani–Fischer synthesis. Nitric acid oxidizes A to an optically active aldaric acid, B to an optically inactive aldaric acid, and C to an optically active aldaric acid. Wohl degradation of C forms D, which is oxidized by nitric acid to an optically active aldaric acid. Wohl degradation of D forms (+)-glyceraldehyde. Identify A, B, C, and D.arrow_forwardA D-aldohexose A is formed from an aldopentose B by the Kiliani-Fischer synthesis. Reduction of A with NABH4 forms an optically inactive alditol. Oxidation of B forms an optically active aldaric acid. What are the structures of A and B?arrow_forwardTreatment with NaBH 4 converts aldose U into an optically inactive (meso) alditol V. Ruff degradation ofU gives W, whose alditol is optically inactive. Ruff degradation of W forms D-glyceraldehyde, thesimplest aldose. Upon Kiliani-Fischer synthesis, U is converted to two aldoses, X and Y. X is oxidized toan optically active aldaric acid Z. Y is oxidized to an optically inactive aldaric acid. Draw the structuresof D-glyceraldehyde, V, W, X, Y, and Z. Structure of compound U is shown below.arrow_forward
- Although reaction occurs in sugars also. H, OH H H-C-OH Oxidizing agent OH OH Н-С-ОН Н-С-ОН C=0 R OH R R R Aldose Aldonic acid anion Ketose Enediol Copyright © 2007 Pearson Prentice Hall, Inc. Draw the reaction above substituting D-fructose instead of the generalized ketose structure shown above (you need to draw all 4 structures). Slan and upload your drawing.arrow_forwardIdentify compounds A–D. A D-aldopentose A is oxidized with HNO3 to an optically inactive aldaric acid B. A undergoes the Kiliani–Fischer synthesis to yield C and D. C is oxidized to an optically active aldaric acid. D is oxidized to an optically inactive aldaric acidarrow_forwardD-Aldopentose A is oxidized to an optically inactive aldaric acid. On Wohl degradation, A forms an aldotetrose B that is oxidized to an optically active aldaric acid. What are the structures of A and B?arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistryChemistryISBN:9781259911156Author:Raymond Chang Dr., Jason Overby ProfessorPublisher:McGraw-Hill EducationPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
- Organic ChemistryChemistryISBN:9780078021558Author:Janice Gorzynski Smith Dr.Publisher:McGraw-Hill EducationChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningElementary Principles of Chemical Processes, Bind...ChemistryISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEY