Question

D-Arabinose can exist in both pyranose and furanose forms.

1. Draw the $\mathbf{\alpha }\mathbf{}\mathbf{and}\mathbf{}\mathbf{\beta }$anomers of D-arabinofuranose.
2. Draw the $\mathbf{\alpha }\mathbf{}\mathbf{and}\mathbf{}\mathbf{\beta }$ anomers of D-arabinopyranose.

Short answer

Answer

(a.)and

(b.)and

Step-by-step solution

Anomers

Anomers are the cyclic saccharides which are epimers at the C1 (anomeric carbon).At C1, the$\mathrm{\alpha }$ anomer has the OH group in the downside, and in the case of $\mathrm{\beta }$anomer, the OH group is in the upside.

The structure of D-Arabinose

The D-Arabinose structure is shown as,

D-Arabinose structure

α and β anomers of D-arabinofuranose

In D-arabinofuranose, at C1, the $\mathrm{\alpha }$anomer has an OH group in the down position.

In the $\mathrm{\beta }$anomer, the OH group is in the up position.

anomers of D-arabinofuranose

α and β anomers of D-arabinopyranose.

In D-arabinopyranose, at C1, the $\mathrm{\alpha }$anomer has an OH group downward.

In the$\mathrm{\beta }$anomer, the OH group is in the upward direction.

$\mathrm{\alpha }\mathrm{and}\mathrm{\beta }$ anomers of D-arabinopyranose