What is meso compound

R,S -2,3-dichlorobutane S,R -2,3-dichlorobutane. However, let's look at the other important conformation of the meso isomer and make sure we can recognise it is the meso isomer.

The relationship of A to B is not immediately obvious. However, once the right hand end has been rotated about the central C-C bond by degrees, A can been seen to be the mirror image of B. A quick way of recognising whether a molecule is achiral is to look for a plane of symmetry.

If you're seeing this message, it means we're having trouble loading external resources on our website. To log in and use all the features of Khan Academy, please enable JavaScript in your browser. Donate Login Sign up Search for courses, skills, and videos. Science Organic chemistry Stereochemistry Stereoisomeric relationships.

Stereoisomers, enantiomers, diastereomers, constitutional isomers and meso compounds. Enantiomers and diastereomers. Meso compounds. Current timeTotal duration Google Classroom Facebook Twitter.

Video transcript - [Instructor] A meso compound is a compound that has chirality centers but is achiral. We're gonna come back to this definition in a few minutes. Right now, let's focus in on this drawing. And our goal is to draw all possible stereoisomers for this dot structure. So we know from earlier videos that this carbon is a chirality center, and so is this one.

And we would expect two to the n stereoisomers, where n is the number of chirality centers. And since we have two chiral centers here, we would expect two to the second power, or four stereoisomers. So this is really just a maximum number, so I'm gonna put a question mark right here. So do we get four stereoisomers? Let's draw out the four possibilities. Our first stereoisomer could have both bromines coming out at us in space.

So let me go ahead and draw that in. So we could have both bromines coming out at us. For the second possibility, we might have both bromines going away from us in space. So I'll draw that in there. For the third possibility, we could have one bromine up and one bromine down. So I'll put those in. And for the fourth, just reverse them. Have the top bromine down and the bottom bromine up. Well, all right, let's examine the relationships between our stereoisomers.

And let's start with stereoisomer possibility three and four. So let's compare these and let's figure out the relationship. On the left is stereoisomer three. We can see there's a bromine coming at us and a bromine going away from us. On the right is stereoisomer four. It lacks the internal mirror plane. They have four chiral centres.

But they are optically inactive because they have internal plane of symmetry. Key Questions Why are meso compounds achiral? Answer: See explanation. Explanation: Meso compounds are achiral because they have a plane of symmetry and this will lead to a mirror image which is superimposable to the original molecule. What is a meso compound?

It has an internal plane of symmetry and we can superimpose it on its own mirror image. Ernest Z. Why are meso compounds achiral? Is it easy recognize a meso compound? How can I identify meso compounds? Is cis -1,2-dibromocyclohexane a meso compound? For example: Another case is when we rotate the whole molecule by degree. Example This molecule has a plane of symmetry the horizontal plane going through the red broken line and, therefore, is achiral; However, it has two chiral carbons and is consequentially a meso compound.

Example 2 This molecules has a plane of symmetry the vertical plane going through the red broken line perpendicular to the plane of the ring and, therefore, is achiral, but has has two chiral centers. Other Examples of meso compounds Meso compounds can exist in many different forms such as pentane, butane, heptane, and even cyclobutane.

Problems Beside meso, there are also other types of molecules: enantiomer, diastereomer , and identical. Answer key: A C, D, E are meso compounds. References Vollhardt, K. Organic Chemistry 5 th Ed. New York: W.