Question

Draw a Haworth projection for each compound using the structures in Figures 28.4 and 28.5.

Short answer

Answer:

a.

b.

c.

Step-by-step solution

Haworth Projection

Haworth projection is the cyclic structure used for presenting the monosaccharides in 3-D. For D-sugar, CH₂OH is drawn up, and in the case of L-sugar, the CH₂OH is drawn down.

Haworth projection of  β-D-talapyranose

a. The $\mathrm{\beta }-\mathrm{D}-\mathrm{talopyranose}$ is a D-sugar means CH₂OH is drawn upwards. It is a $\mathrm{\beta }$anomer, and this means OH is up at C1.

Haworth projection of$\mathrm{\beta }-\mathrm{D}-\mathrm{talopyranose}$

Haworth projection of α-D-galactopyranose

b. The $\mathrm{\alpha }-\mathrm{D}-\mathrm{galactopyranose}$is a D-sugar means CH₂OH is drawn upwards. It is an $\mathrm{\alpha }$anomer, and this means OH is down at C1.

Haworth projection of$\mathrm{\alpha }-\mathrm{D}-\mathrm{galactopyranose}$

Haworth projection of α-D-tagatofuranose

The $\mathrm{\alpha }-\mathrm{D}-\mathrm{tagatofuranose}$is a D-sugar means CH₂OH is drawn upwards. It is an $\mathrm{\alpha }$anomer, and this means OH is down at C1.

Haworth projection of$\mathrm{\alpha }-\mathrm{D}-\mathrm{tagatofuranose}$