/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q32P Ruff degradation of D-arabinose ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 23: Q32P (page 1231)

Ruff degradation of D-arabinose gives D-erythrose. The Kiliani-Fischer synthesis converts D-erythrose to a mixture of D-arabinose and D-ribose. Draw out these reactions and give the structure of D-ribose.

Short Answer

Expert verified

D-arabinose D-erythrose D-arabinose D-ribose

Step by step solution

01

Step-1.

Ruff degradation is employed when carbohydrate chain needs to be shortened or degraded by a single carbon. Aqueous solution of bromine is used in first step which is used for oxidation of aldehyde to carboxylic acid and then in second step, ferric ion catalyses oxidation reaction with hydrogen peroxide and bond cleavage between carbon-1 and carbon-2 occurs forming an aldehyde. D-arabinose on Ruff degradation gets converted to D-erythrose.

D-arabinose D-erythrose

02

Step-2.

Kiliani-Fischer synthesis is employed when carbohydrate chain needs to be lengthened by one carbon. It involves addition of cyanide ion to aldoses which is then partially reduced and hydrolysed to give a new aldehyde. Kiliani-Fischer synthesis converts D-erythrose into mixture of D-arabinose and D-ribose. A new chiral carbon is generated in this process and due to this, position of hydroxyl group can be on left or right. That鈥檚 why we got two products, that is, D-arabinose and D-ribose. Diastereomeric mixture is obtained or products which are diastereomers of each other.

D-erythrose D-arabinose D-ribose

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

After a series of Kiliani鈥揊ischer syntheses on (+)-glyceraldehyde, an unknown sugar is isolated from the reaction mixture. The following experimental information is obtained:

(1) Molecular formula C6H12O6

(2) Undergoes mutarotation.

(3) Reacts with bromine water to give an aldonic acid.

(4) Reacts with HNO3 to give an optically active aldaric acid.

(5) Ruff degradation followed by HNO3 oxidation gives an optically inactive aldaric acid. (6) Two Ruff degradations followed by HNO3 oxidation give meso-tartaric acid.

(7) When the original sugar is treated with CH3I and Ag2O, a pentamethyl derivative is formed. Hydrolysis gives a tetramethyl derivative with a free hydroxy group on C5.

(a) Draw a Fischer projection for the open-chain form of this unknown sugar. Use Figure 23-3 to name the sugar.

(b) Draw the most stable conform

Aldohexoses A and B both undergo Ruff degradation to give aldopentose C. On treatment with warm nitric acid, aldopentose C gives an optically active aldaric acid. B also reacts with warm nitric acid to give an optically active aldaric acid, but A reacts to give an optically inactive aldaric acid. Aldopentose C is degraded to aldotetrose D, which gives optically active tartaric acid when it is treated with nitric acid. Aldotetrose D is degraded to (+)-glyceraldehyde. Deduce the structures of sugars A,B,C and D, and use Figure 23-3 to determine the correct names of these sugars.

Draw and name the enantiomers of the sugars shown in Figure 23-2. Give the relative configuration (D or L) and the sign of the rotation in each case.

Draw the Haworth projection for the cyclic structure of D-mannose by laying down the Fischer projection.

Treatment of either anomer of fructose with excess ethanol in the presence of a trace of HCI gives a mixture of the 伪 and 尾 anomers of ethyl-D-fructofuranoside. Draw the starting materials, reagents, and products for this reaction. Circle the aglycone in each product.
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation

Organic Chemistry

Read Explanation

Kinetics

Read Explanation

Nuclear Chemistry

Read Explanation

The Earths Atmosphere

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.