Question

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

1. $\mathbf{\beta }\mathbf{-}\mathbf{D}\mathbf{-}\mathbf{talopyranose}$
2. $\mathbf{\alpha }\mathbf{-}\mathbf{D}\mathbf{-}\mathbf{galactopyranose}$
   
3. $\mathbf{\alpha }\mathbf{-}\mathbf{D}\mathbf{-}\mathbf{tagatofuranose}$

Short answer

Answer

a.

b.

c.

Step-by-step solution

Step-by-Step Solution Step 1: Haworth Projection

Haworth projection is the cyclic structure used for presenting the monosaccharides in 3-D.For D-sugar, ${\mathrm{CH}}_2\mathrm{OH}$ is drawn up, and in the case of L-sugar, the is drawn down.

Haworth projection of  β-D-talopyranose

a. The $\mathrm{\beta }-\mathrm{D}-\mathrm{talopyranose}$is a D-sugar means ${\mathrm{CH}}_2\mathrm{OH}$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${\mathrm{CH}}_2\mathrm{OH}$is drawn upwards. It is anlocalid="1648627008192" $\mathrm{\alpha }$anomer, and this means OH is down at C1.

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

Haworth projection of α-D-tagatofuranose

c. The $\mathrm{\alpha }-\mathrm{D}-\mathrm{tagatofuranose}$is a D-sugar means ${\mathrm{CH}}_2\mathrm{OH}$is drawn upwards. It is $\mathrm{\alpha }$an anomer, and this means OH is down at C1.

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