Question

Draw the$\mathbf{\beta }$ anomer of a monosaccharide epimeric with D-glucose at C2 using a Haworth projection.

Short answer

Answer

Step-by-step solution

Step-by-Step SolutionStep 1: Anomers

Anomers constitute stereoisomers that happen because of the variation in configuration at the anomeric carbon. The anomeric carbon is also termed the acetal/hemiacetal carbon.

Haworth projection

A monosaccharide’s cyclic structure can be indicated in a three dimensional form by the Haworth projection. These structures are used to portray cyclic sugars. Haworth projections are important in several fields like organic chemistry and biochemistry.

Step 3: β anomer of a monosaccharide epimeric with D-glucose at C2

For the $\mathrm{\beta }$-D glucose C2 anomer, glucofuranose ring is created by the attack of OH substituent found at the fifth carbon on the carbonyl carbon(C2). In the beta anomer at C2, the substitutent ${\mathrm{CH}}_2\mathrm{OH}$at C5 and OH at C2 are cis to each other. Hence, both are drawn above the ring.

The substitutents present on the right side in the Fischer projection are drawn below the ring in the Haworth projection. The substituents present on the left side are drawn above the ring in Haworth projection.

The anomer for a monosaccharide epimeric with D-glucose at C2 using the Haworth projection can be given as:

C2 anomer of $\mathrm{\beta }$-D glucose

C2 anomer of $\mathrm{\beta }$-D-glucofuranose