Exam 20: The Organic Chemistry of Carbohydrates

Which of the following corresponds to the definition of an aldopentose? I.It is a monosaccharide. II)It contains a CHO group III)It is a disaccharide. IV)It is an oligosaccharide.

Cell-surface carbohydrates play an important role in

Provide the structure of the more stable chair conformer which results when β-D-galactose is treated with excess acetic anhydride/pyridine.

Give the major product(s)for the following reaction.You may choose more than one answer.

Which of the following would give a positive Tollen's test?

When D-sorbose (shown below)is treated with NaBH₄,which of the following is produced?

When pure α-D-glucopyranose is dissolved in water,the optical rotation of the resulting solution changes over a period of time.What is the name of this phenomenon and why does it occur?

Given the structure of D-altrose below,provide the Haworth structure of β-D-altropyranose.

Which of the following statements best describes the meaning of a glycoside?

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

When D-tagatose is added to a basic aqueous solution,an equilibrium mixture of three monosaccharides is obtained.Identify the monosaccharides.

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

Which monosaccharides are formed in the Kiliani-Fischer synthesis starting with D-xylose?

How many chirality centers are there in an aldohexose?

Epimers are essentially

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

Which of the following compounds is a D-sugar?

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

Two D-aldopentoses give the same D-aldotetrose upon Ruff degradation.The two aldopentoses are

Provide the structure of the product which results when D-ribose is treated with bromine water.