What is the value of specific rotation exhibited by glucose molecule?
What is the value of specific rotation exhibited by glucose molecule?
$+52.7^{\circ}$
$-92.4^{\circ}$
$+66.5^{\circ}$
$+40.3^{\circ}$
Solution
The specific rotation of glucose is the result of the specific rotations of its two anomers, $\alpha$-D-glucopyranose and $\beta$-D-glucopyranose.
The specific rotation of $\alpha-D-g l u c o p y r a n o s e ~ i s ~+112^{\circ}$, and the specific rotation of $\beta$ -D-glucopyranose is $+19^{\circ}$.
When dissolved in water, the specific rotation of either anomer changes over time, eventually reaching a value of $+52^{\circ}$. This is called mutarotation.