Question 1

How many stereoisomers are possible for a 2-ketohexose?

Accepted Answer

A) 2 
B) 4 
C) 8 
D) 16 
E) 32 
A) 2 
B) 4 
C) 8 
D) 16 
E) 32

Question 2

An optically active D-aldopentose produced an optically active alditol upon treatment with NaBH4.When this aldopentose was subjected to a Ruff degradation,a D-aldotetrose was generated.This aldotetrose gave an optically active aldaric acid upon oxidation with HNO3.Use these data to provide the structure of the starting D-aldopentose.

Accepted Answer

Question 3

What is the relationship between the following compounds?

Accepted Answer

A) conformational isomers 
B) constitutional isomers 
C) identical 
D) enantiomers 
E) diastereomers 
A) conformational isomers 
B) constitutional isomers 
C) identical 
D) enantiomers 
E) diastereomers

Question 4

Which of the following is the Haworth projection of β-D-galactopyranose?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 5

Which of the following blood types is known as the universal donor?

Accepted Answer

A) A 
B) B 
C) AB 
D) O 
E) ABO 
A) A 
B) B 
C) AB 
D) O 
E) ABO

Question 6

A D-erythrose is described as a(n)

Accepted Answer

A) aldopentose. 
B) ketopentose. 
C) aldohexose. 
D) ketohexose. 
E) none of the above. 
A) aldopentose. 
B) ketopentose. 
C) aldohexose. 
D) ketohexose. 
E) none of the above.

Question 7

Give the major product(s)for the reaction.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 8

Draw the Fischer projection for the open-chain form of D-erythrose.

Accepted Answer

The answer of Draw the Fischer projection for the open-chain...

Question 9

At which carbon are the following sugars epimers of each other?

Accepted Answer

A) C-1 
B) C-2 
C) C-3 
D) C-4 
E) C-5 
A) C-1 
B) C-2 
C) C-3 
D) C-4 
E) C-5

Question 10

An aqueous solution of glucose behaves as an aldehyde because

Accepted Answer

A) it is hydrolyzed by water to the free aldehyde. 
B) it is a ketone,but is in equilibrium with the aldehyde form. 
C) glucose is actually a cyclic aldehyde. 
D) its cyclic hemiacetal,the predominant form,is in equilibrium with the free aldehyde form. 
E) it can be oxidized with periodic acid. 
A) it is hydrolyzed by water to the free aldehyde. 
B) it is a ketone,but is in equilibrium with the aldehyde form. 
C) glucose is actually a cyclic aldehyde. 
D) its cyclic hemiacetal,the predominant form,is in equilibrium with the free aldehyde form. 
E) it can be oxidized with periodic acid.

Question 11

Name the following compound.

Accepted Answer

A) D-glucose 
B) D-galactose 
C) D-fructose 
D) D-arabinose 
E) D-talose 
A) D-glucose 
B) D-galactose 
C) D-fructose 
D) D-arabinose 
E) D-talose

Question 12

Which of the following is/are the product(s)obtained from the reduction of D-fructose?

Accepted Answer

A)    
B)    
C)    
D) A and B 
E) A and C 
A)    
B)    
C)    
D) A and B 
E) A and C

Question 13

The open-chain form of D-idose is shown below.Draw the Haworth projection of a-D-idopyranose.

Accepted Answer

The answer of The open-chain form of D-idose is shown...

Question 14

Give the name for the following compound.

Accepted Answer

A) 4-O-(a-D-glucopyranosyl)-a-D-glucopyranose 
B) 4-O-(a-D-glucopyranosyl)-b-D-glucopyranose 
C) 4-O-(b-D-glucopyranosyl)- a-D-glucopyranose 
D) 4-O-(b-D-glucopyranosyl)- b-D-glucopyranose 
E) 4-O-(b-D-galactopyranosyl)-a-D-glucopyranose 
A) 4-O-(a-D-glucopyranosyl)-a-D-glucopyranose 
B) 4-O-(a-D-glucopyranosyl)-b-D-glucopyranose 
C) 4-O-(b-D-glucopyranosyl)- a-D-glucopyranose 
D) 4-O-(b-D-glucopyranosyl)- b-D-glucopyranose 
E) 4-O-(b-D-galactopyranosyl)-a-D-glucopyranose

Question 15

Reduction of a 2-ketohexose with NaBH4 yields

Accepted Answer

A) a single aldohexose. 
B) a mixture of acetals. 
C) a mixture of alditols. 
D) a mixture of cyclic hemiacetals. 
E) a single pyranose. 
A) a single aldohexose. 
B) a mixture of acetals. 
C) a mixture of alditols. 
D) a mixture of cyclic hemiacetals. 
E) a single pyranose.

Question 16

Which of the following statements best describes the meaning of mutorotation?

Accepted Answer

A) a rapid exchange between the α and β forms of diasternomeric sugars 
B) a rapid exchange between the D and L forms 
C) a slow exchange between hydrogen and deuterated hydrogen 
D) a slow change in optical rotation to reach an equilibrium value 
E) a slow change in absolute configuration to reach an equilibrium value 
A) a rapid exchange between the α and β forms of diasternomeric sugars 
B) a rapid exchange between the D and L forms 
C) a slow exchange between hydrogen and deuterated hydrogen 
D) a slow change in optical rotation to reach an equilibrium value 
E) a slow change in absolute configuration to reach an equilibrium value

Question 17

Which of the following sugars yields the same alditol upon reduction with NaBH4 as does D-glucose?

Accepted Answer

A) D-fructose 
B) D-mannose 
C) L-glucose 
D) D-arabinose 
E) none of the above 
A) D-fructose 
B) D-mannose 
C) L-glucose 
D) D-arabinose 
E) none of the above

Question 18

When a monosaccharide reacts to give the pyranose form from its open-chain form,how many distinct pyranose forms are possible?

Accepted Answer

A) 1 
B) 2 
C) 2n,where n is the number of carbons present 
D) 4n + 2,where n is the number of carbons present 
E) 4 
A) 1 
B) 2 
C) 2n,where n is the number of carbons present 
D) 4n + 2,where n is the number of carbons present 
E) 4

Question 19

Under what conditions is the methyl glycoside of galactose prepared?

Accepted Answer

CH₃OH,H+ (n

Question 20

Given the structure of D-talose below,provide the Haworth structure of α-D-talopyranose.

Accepted Answer

The answer of Given the structure of D-talose below,provide the...

Exam 20: The Organic Chemistry of Carbohydrates

How many stereoisomers are possible for a 2-ketohexose?

What is the relationship between the following compounds?

Which of the following is the Haworth projection of β-D-galactopyranose?

Which of the following blood types is known as the universal donor?

A D-erythrose is described as a(n)

Give the major product(s)for the reaction.

Draw the Fischer projection for the open-chain form of D-erythrose.

At which carbon are the following sugars epimers of each other?

An aqueous solution of glucose behaves as an aldehyde because

Name the following compound.

Which of the following is/are the product(s)obtained from the reduction of D-fructose?

The open-chain form of D-idose is shown below.Draw the Haworth projection of a-D-idopyranose.

Give the name for the following compound.

Reduction of a 2-ketohexose with NaBH4 yields

Which of the following statements best describes the meaning of mutorotation?

Which of the following sugars yields the same alditol upon reduction with NaBH4 as does D-glucose?

When a monosaccharide reacts to give the pyranose form from its open-chain form,how many distinct pyranose forms are possible?

Under what conditions is the methyl glycoside of galactose prepared?

Given the structure of D-talose below,provide the Haworth structure of α-D-talopyranose.

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds: Nomenclature, physical Properties, and Structure

Isomers: the Arrangement of Atoms in Space

Alkenes: Structure,nomenclature,and an Introduction to Reactivity - Thermodynamics and Kinetics

The Reactions of Alkenes - the Stereochemistry of Addition Reactions

The Reactions of Alkynes - Introduction to Multistep Synthesis

Delocalized Electrons: Their Effect on Stability, pka, and the Products of a Reaction - Aromaticity and Electronic Effects: an Introduction to the Reactions of Benzene

Substitution and Elimination Reactions of Alkyl Halides

Reactions of Alcohols, ethers, epoxides, amines and Sulfur-Containing Compounds

Organometallic Compounds

Radicals

Mass Spectrometry,infrared Spectroscopy,and Uvvis Spectroscopy

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Α-Carbon

Reactions of Benzene and Substituted Benzenes

More About Amines - Reactions of Heterocylic Compounds

Amino Acids,peptides,and Proteins

Catalysis in Organic Reactions and in Enzymatic Reactions

The Organic Chemistry of the Coenzymes, compounds Derived From Vitamins

The Organic Chemistry of the Metabolic Pathways

The Organic Chemistry of Lipids

The Chemistry of the Nucleic Acids

Synthetic Polymers

Pericyclic Reactions

Filters

Reduction of a 2-ketohexose with NaBH₄ yields

Which of the following sugars yields the same alditol upon reduction with NaBH₄ as does D-glucose?