91Ó°ÊÓ

What are the differences in the Fischer projections of D-galactose and L-galactose? (13.3)

What are the differences in the Haworth structures of $\mathrm{Î\pm }$-D-glucose and $\mathrm{β}$-D-glucose? (13.4)

What are the functional groups and number of carbons in a ketopentose?

Use the Fischer projection for D-gulose in problem $13.69$to answer each of the following: $(13.3,13.5)$

a. Draw the Fischer projection and name the product formed by the reduction of D-gulose.

b. Draw the Fischer projection and name the product formed by the oxidation of D-gulose.

D-Sorbitol, a sweetener found in seaweed and berries, contains only hydroxyl functional groups. When D-sorbitol is oxidized, it forms D-glucose. Draw the Fischer projection for D-sorbitol.$(13.3,13.5)$

D-Erythritol is$70\%$ as sweet as sucrose and contains only hydroxyl functional groups. When D-erythritol is oxidized it forms D-erythrose. Draw the Fischer projection for D-erythritol.$(13.3,13.5)$

$\mathrm{Î\pm }$-Cellobiose is a disaccharide obtained from the hydrolysis of cellulose. It is quite similar to maltose except it has a $\mathrm{β}(1→4)$-glycosidic bond. Draw the Haworth structure for$\mathrm{Î\pm }-$cellobiose. (13.4, 13.6)

The disaccharide trehalose found in mushrooms is composed of two $\mathrm{Î\pm }$-D-glucose molecules joined by an $\mathrm{Î\pm }(1→1)$-glycosidic bond. Draw the Haworth structure for trehalose. (13.4,13.6)

Gentiobiose is found in saffron.$(13.4,13.5,13.6)$

a. Gentiobiose contains two glucose molecules linked by a $\mathrm{β}(1→6)$-glycosidic bond. Draw the Haworth structure for $\mathrm{β}$-gentiobiose.

b. Is gentiobiose a reducing sugar? Explain.

Identify the Fischer projection A to D that matches each of the following: (13.1, 13.3)

a. the L enantiomer of mannose

b. a ketopentose

c. an aldopentose

d. a ketohexose