Question 1

Suggest a simple chemical test that you might use to distinguish between 2,3-pentanediol and 2,4-pentanediol?

Accepted Answer

Periodic acid test: 2,3-pentanediol is e

Question 2

What products are expected to be formed upon subjecting l-erythrose (shown below)to the following reaction sequence? (Draw Fischer projection formulas)
i)HCN; ii)Ba(OH)2; iii)H3O+; iv)Na(Hg),H2O,pH 3-5

Accepted Answer

Kiliani-Fi

Question 3

Consider the structures below: what term(s)describe(s)the relationship between them?

Accepted Answer

A) Enantiomers 
B) Epimers 
C) Diastereomers 
D) Anomers 
E) More than one of these choices. 
A) Enantiomers 
B) Epimers 
C) Diastereomers 
D) Anomers 
E) More than one of these choices.

Question 4

Refer to the structures below.Which sugars would react with phenylhydrazine to yield the same phenylosazone?

Accepted Answer

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

Question 5

What is the mechanism of the hydrolysis of maltose to glucose under acidic conditions?

Accepted Answer

The answer of What is the mechanism of the hydrolysis...

Question 6

Which of the following would yield d-glucose and d-mannose when subjected to a Kiliani-Fischer synthesis?

Accepted Answer

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

Question 7

An unknown pentose Z reacts with NaBH4 to give an optically inactive compound.The pentose Z gives the same osazone as arabinose.What carbohydrate is Z?

Accepted Answer

A) Fructose 
B) Ribose 
C) Xylose 
D) Glucose 
E) Lyxose 
A) Fructose 
B) Ribose 
C) Xylose 
D) Glucose 
E) Lyxose

Question 8

An aldopentose,X,is subjected to a Kiliani-Fischer synthesis to produce two aldohexoses,Y and Z.Both Y and Z,when oxidized with nitric acid,yield optically active aldaric acids.Which structure represents X?

Accepted Answer

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

Question 9

Which would undergo mutarotation in neutral aqueous solution?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) I,II and III 
A) I 
B) II 
C) III 
D) IV 
E) I,II and III

Question 10

Complete hydrolysis of heparin gives:

Accepted Answer

A) "$\beta$-N-Acetylmuramic acid and $\beta$-d-glucosamine." 
B) "$\beta$-d-Glucosamine and glucuronate-2-sulfate." 
C) "d-Glucuronate-2-sulfate and N-sulfo-3-glucosamine-6-sulfate." 
D) "Glucose sulfate and maltose. 
E) "Chitin and d-glucurunate-2-sulfate." 
A) "$\beta$-N-Acetylmuramic acid and $\beta$-d-glucosamine." 
B) "$\beta$-d-Glucosamine and glucuronate-2-sulfate." 
C) "d-Glucuronate-2-sulfate and N-sulfo-3-glucosamine-6-sulfate." 
D) "Glucose sulfate and maltose. 
E) "Chitin and d-glucurunate-2-sulfate."

Question 11

Which reagent would cause the following conversion to take place?

Accepted Answer

A) Excess CH3OH and KOH 
B) Excess CH3OH and HCl 
C) Excess (CH3)2SO4 and OH- 
D) Excess CH3I and H3O+ 
E) Excess (CH3CO)2O 
A) Excess CH3OH and KOH 
B) Excess CH3OH and HCl 
C) Excess (CH3)2SO4 and OH- 
D) Excess CH3I and H3O+ 
E) Excess (CH3CO)2O

Question 12

Why can cellulose not serve as a food source for humans?

Accepted Answer

Because the enzymes of humans

Question 13

What is the structure for A?

Accepted Answer

The answer of What is the structure for A? ...

Question 14

Bromine water is a reagent that converts an aldose to an ___.

Accepted Answer

The answer of Bromine water is a reagent that converts...

Question 15

Consider the structure of d-allose below:   Which of the following structures represents l-allose?

Accepted Answer

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

Question 16

Epimers are represented by:

Accepted Answer

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

Question 17

Which of the following substances will afford an optically inactive product upon reaction with nitric acid?

Accepted Answer

A) I 
B) II 
C) III and IV 
D) II,III and IV 
E) All of these choices. 
A) I 
B) II 
C) III and IV 
D) II,III and IV 
E) All of these choices.

Question 18

Carbohydrates are synthesized in green plants by ___.

Accepted Answer

The answer of Carbohydrates are synthesized in green plants by...

Question 19

Provide the structure of ethyl α-d-mannoside in Haworth projection.

Accepted Answer

The answer of Provide the structure of ethyl α-d-mannoside in...

Question 20

Which of the following substances will afford a meso product upon reaction with Br2/H2O?

Accepted Answer

A) I 
B) II 
C) III and IV 
D) II,III and IV 
E) None of these choices. 
A) I 
B) II 
C) III and IV 
D) II,III and IV 
E) None of these choices.

Exam 22: Carbohydrates

Suggest a simple chemical test that you might use to distinguish between 2,3-pentanediol and 2,4-pentanediol?

What products are expected to be formed upon subjecting l-erythrose (shown below)to the following reaction sequence? (Draw Fischer projection formulas) i)HCN; ii)Ba(OH)2; iii)H3O+; iv)Na(Hg),H2O,pH 3-5

Consider the structures below: what term(s)describe(s)the relationship between them?

Refer to the structures below.Which sugars would react with phenylhydrazine to yield the same phenylosazone?

What is the mechanism of the hydrolysis of maltose to glucose under acidic conditions?

Which of the following would yield d-glucose and d-mannose when subjected to a Kiliani-Fischer synthesis?

An unknown pentose Z reacts with NaBH4 to give an optically inactive compound.The pentose Z gives the same osazone as arabinose.What carbohydrate is Z?

An aldopentose,X,is subjected to a Kiliani-Fischer synthesis to produce two aldohexoses,Y and Z.Both Y and Z,when oxidized with nitric acid,yield optically active aldaric acids.Which structure represents X?

Which would undergo mutarotation in neutral aqueous solution?

Complete hydrolysis of heparin gives:

Which reagent would cause the following conversion to take place?

Why can cellulose not serve as a food source for humans?

What is the structure for A?

Bromine water is a reagent that converts an aldose to an ___.

Consider the structure of d-allose below: Which of the following structures represents l-allose?

Epimers are represented by:

Which of the following substances will afford an optically inactive product upon reaction with nitric acid?

Carbohydrates are synthesized in green plants by ___.

Provide the structure of ethyl α-d-mannoside in Haworth projection.

Which of the following substances will afford a meso product upon reaction with Br2/H2O?

The Basics

Families of Carbon

Acids and Bases

Nomenclature and Conformations of Alkanes and Cycloalkanes

Stereochemistry

Nucleophilic Reactions

Alkenes and Alkynes I

Alkenes and Alkynes II

Nuclear Magnetic Resonance and Mass Spectrometry

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Reactions at the Α Carbon of Carbonyl Compounds

Condensation and Conjugate Addition Reactions of Carbonyl Compounds

Amines

Transition Metal Complexes

Lipids

Amino Acids and Proteins

Nucleic Acids and Protein Synthesis

Filters

What products are expected to be formed upon subjecting l-erythrose (shown below)to the following reaction sequence? (Draw Fischer projection formulas) i)HCN; ii)Ba(OH)₂; iii)H₃O⁺; iv)Na(Hg),H₂O,pH 3-5

An unknown pentose Z reacts with NaBH₄ to give an optically inactive compound.The pentose Z gives the same osazone as arabinose.What carbohydrate is Z?

Which of the following substances will afford a meso product upon reaction with Br₂/H₂O?