Chapter 24.5, Problem 19CC

(a)

Interpretation Introduction

Interpretation:

Furanose forms of D-Erythrose and D-Threose are needed to be drawn.

Concept introduction:

• Furanose is used to represent sugars in their cyclic forms. In which five-membered ring consisting of four carbon atoms and one oxygen atom.
• The –OH group of C4 carbon attacks the carbonyl group of the D-aldotetroses, thereby a Furanose ring is formed by the four carbon atoms and oxygen atom of –OH group in the C4 carbon with incorporating into the ring.
• α-indicates the –OH group of anomeric carbon C1 is directed to down side.
• β-indicates the –OH group of anomeric carbon C1 is directed to upward side.
• The right side and left side –OH groups of chiral carbons in fisher projection are drawn as down side and upward side respectively.

To draw: the Furanose form of α-D-Erythrofuranose.

(b)

Interpretation Introduction

Interpretation:

Furanose forms of D-Erythrose and D-Threose are needed to be drawn.

Concept introduction:

• Furanose is used to represent sugars in their cyclic forms. In which five-membered ring consisting of four carbon atoms and one oxygen atom.
• The –OH group of C4 carbon attacks the carbonyl group of the D-aldotetroses, thereby a Furanose ring is formed by the four carbon atoms and oxygen atom of –OH group in the C4 carbon with incorporating into the ring.
• α-indicates the –OH group of anomeric carbon C1 is directed to down side.
• β-indicates the –OH group of anomeric carbon C1 is directed to upward side.
• The right side and left side –OH groups of chiral carbons in fisher projection are drawn as down side and upward side respectively.

To draw: the Furanose form of β-D-Erythrofuranose.

(c)

Interpretation Introduction

Interpretation:

Furanose forms of D-Erythrose and D-Threose are needed to be drawn.

Concept introduction:

• Furanose is used to represent sugars in their cyclic forms. In which five-membered ring consisting of four carbon atoms and one oxygen atom.
• The –OH group of C4 carbon attacks the carbonyl group of the D-aldotetroses, thereby a Furanose ring is formed by the four carbon atoms and oxygen atom of –OH group in the C4 carbon with incorporating into the ring.
• α-indicates the –OH group of anomeric carbon C1 is directed to down side.
• β-indicates the –OH group of anomeric carbon C1 is directed to upward side.
• The right side and left side –OH groups of chiral carbons in fisher projection are drawn as down side and upward side respectively.

To draw: the Furanose form of α-D-Threofuranose.

(d)

Interpretation Introduction

Interpretation:

Furanose forms of D-Erythrose and D-Threose are needed to be drawn.

Concept introduction:

• Furanose is used to represent sugars in their cyclic forms. In which five-membered ring consisting of four carbon atoms and one oxygen atom.
• The –OH group of C4 carbon attacks the carbonyl group of the D-aldotetroses, thereby a Furanose ring is formed by the four carbon atoms and oxygen atom of –OH group in the C4 carbon with incorporating into the ring.
• α-indicates the –OH group of anomeric carbon C1 is directed to down side.
• β-indicates the –OH group of anomeric carbon C1 is directed to upward side.
• The right side and left side –OH groups of chiral carbons in fisher projection are drawn as down side and upward side respectively.

To draw: the Furanose form of β-D-Threofuranose.