Question

A vicinal diol has two alcoholic groups present:
A.on the same carbon
B.on adjacent carbon
C.anywhere along with the carbon
D.none of the above

Answer 1

Hint: We know that there are two types of groups one is vicinal and one is a geminal diol. One group has two hydroxyl groups on the same carbon and the other has two hydroxyl groups on different carbon.

Complete step by step answer:
We know that the vicinal meaning is adjacent or neighboring.
Let us see the example of vicinal diol:


As we can see that the two alcoholic groups are present on the adjacent carbon in vicinal diol.

Therefore, we can conclude that the correct answer to this question is option B.

Additional Information:
Let us see the structure of geminal diol to understand the difference between vicinal alcohol and geminal alcohol.


As we can see that the two alcoholic groups are present on the same carbon in geminal diol.
We know that in a vicinal diol, the two hydroxyl groups occupy neighboring positions, that is, they are attached to adjacent atoms and these compounds are called glycols. Examples include 1,2-ethanediol or ethylene glycol \[HO - {(C{H_2})_2} - OH\], a common ingredient of antifreeze products. Another example is propane-1,2-diol, or alpha propylene glycol, \[HO - C{H_2} - CH\left( {OH} \right) - C{H_3}\], used in the food and medicine industry, as well as a relatively non-poisonous antifreeze product.
We most know that on commercial scales, the main route to vicinal diols is the hydrolysis of epoxides and the epoxides are prepared by epoxidation of the alkene.

Note: We can get confused between the vicinal and geminal alcohol and we must know the placement of the alcoholic group on the adjacent carbon atom and same carbon atom respectively. So, option A and option C can be neglected.