Exam 20: The Organic Chemistry of Carbohydrates

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

Given the structure of D-arabinose below,provide the structure of the glycoside methyl α-D-arabinofuranoside.

What nucleophilic carbon species is used in the Kiliani-Fischer synthesis?

Which of the following statements best describes the difference between amylose and amylopectin?

Give the major product(s)for the following reaction.

Give the product(s)for each step of the following reaction.

Anomers of D-glucopyranose differ in their stereochemistry at

Draw the enolate of D-glucose.

Give the common name for the following structure.

Fructose is described as a(n)

Name the following structure.

When α-D-xylofuranose is treated with excess methyl iodide in the presence of Ag₂O,how many equivalents of methyl iodide react with each equivalent of the furanose?

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

Provide the Haworth projection of ethyl-β-D-mannopyranoside.

Give the name for the following structure.

Which of the following is true about sucrose?

An optically active D-aldopentose produced an optically inactive 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.

When D-threose is treated with NaBH₄

How many chirality centers are there in a 2-ketohexose?

Which of the following represents a glycosidic bond?