Concept explainers
Interpretation:
The reactions for Ruff degradation of D-arabinose and Kiliani Fischer synthesis of D-erythrose are to be shown and the structure of D-ribose is to be drawn.
Concept introduction:
Ruff degradation is a method which is used to shorten sugar chain. It is a two step process which starts with a bromine-water oxidation of the aldose to its aldonic acid. Then in the second step treatment of aldonic acid with hydrogen peroxide and ferric sulfate oxidizes the carbonyl group to
The Kiliani Fischer synthesis is a method of lengthening an aldose carbon chain by adding one carbon atom to the
Ruff degradation and Kiliani Fischer synthesis are the opposite methods of each other.
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Organic Chemistry (9th Edition)
- Draw the products from Killiani-Fischer reaction of D-ribose and L-Xylose.arrow_forwardd-Altrose is an aldohexose. Ruff degradation of d-altrose gives the same aldopentose asdoes degradation of d-allose, the C3 epimer of glucose. Give the structure of d-altrosearrow_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
- A 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_forwardThe following observations are obtained after a D-hexose was made to react with several reagents: (1) The reactions of a D-hexose with (a) to (d) below yields an aldaric acid (a) NH₂OH, (b) (CH3CO)₂O, NaOCOCH 3, and, (c) NaOCH3, and then, (d) HNO3, H₂O (2) HNO3 oxidation of the same D-hexose gives an aldaric acid. Predict the structures of the three (3) possible hexoses that can undergo the above reactions?arrow_forwardAldohexoses 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_forward
- If lactose is first hydrolyzed (by addition of sulfuric acid) into its constituent monosaccharide, and then subjected to complete methylation, what methylated products do you expect?arrow_forwardIn 1891, Emil Fischer determined the structures of glucose and the seven other d-aldohexoses using only simple chemical reactions and clever reasoning about stereochemistry andsymmetry. He received the Nobel Prize for this work in 1902. Fischer had determined thatd-glucose is an aldohexose, and he used Ruff degradations to degrade it to (+)-glyceraldehyde. Therefore, the eight d-aldohexose structures shown in Figure 23-3 are the possiblestructures for glucose.Pretend that no names are shown in Figure 23-3 except for glyceraldehyde, and usethe following results to prove which of these structures represent glucose, mannose,arabinose, and erythrose.(a) Upon Ruff degradation, glucose and mannose give the same aldopentose: arabinose.Nitric acid oxidation of arabinose gives an optically active aldaric acid. What are thetwo possible structures of arabinose?(b) Upon Ruff degradation, arabinose gives the aldotetrose erythrose. Nitric acid oxidation of erythrose gives an optically inactive…arrow_forwardIn 1891, Emil Fischer determined the structures of glucose and the seven other d-aldohexoses using only simple chemical reactions and clever reasoning about stereochemistry andsymmetry. He received the Nobel Prize for this work in 1902. Fischer had determined thatd-glucose is an aldohexose, and he used Ruff degradations to degrade it to (+)-glyceraldehyde. Therefore, the eight d-aldohexose structures shown in Figure 23-3 are the possiblestructures for glucose.Pretend that no names are shown in Figure 23-3 except for glyceraldehyde, and usethe following results to prove which of these structures represent glucose, mannose,arabinose, and erythrose.(a) Upon Ruff degradation, glucose and mannose give the same aldopentose: arabinose.Nitric acid oxidation of arabinose gives an optically active aldaric acid. What are thetwo possible structures of arabinose?(b) Upon Ruff degradation, arabinose gives the aldotetrose erythrose. Nitric acid oxidation of erythrose gives an optically inactive…arrow_forward
- The reagent periodate (IO,") oxidatively cleaves the carbon-carbon bonds between two adjacent carbons carrying hydroxyl groups. Explain how pe- riodate oxidation might be used to distinguish between methyl glycosides of glucose in the pyranose and furanose forms.arrow_forwardWhich D-aldopentoses are reduced to optically inactive alditols using NaBH4, CH3OH?arrow_forwardWhat is the product (from the image below) of the starting material D-glyceraldehyde which will (1) produce aldaric acid upon reacting with HNO3 + H2O, NaOCH2, NH2OH, and (CH3CO)2O + NaOCOCH3 (2) produce tartaric acid upon reacting with HNO3 + H2O, NaOCH3, NH2OH, and (CH3CO)2O + NaOCOCH3arrow_forward
- EBK A SMALL SCALE APPROACH TO ORGANIC LChemistryISBN:9781305446021Author:LampmanPublisher:CENGAGE LEARNING - CONSIGNMENT