Enantiomers vs Diastereomers - Video Tutorials & Practice Problems

Enantiomers vs Diastereomers Concept 1

In this video, we're going to take a look at enim versus Dier. Now first recall that stereo isomers have same molecular formula and connectivity but different spatial orientation. When we talk about anatom anatom themselves are Cairo molecules with non superimposable mirror image of each other. Basically, this means when you're comparing two chiral molecules to one another, when they have opposite configurations of each other at all, their chiral centers, they are an tumors of each other dimmers. Diams are stereo isomers that are not mirror images of each other. So how do you tell if two things are ditherers of each other? Well, when you're comparing the two to each other, some of the chiral centers will be the same in both structures and some of them will be different. That's how we're able to tell the difference between ditherers and enim en animes. All of the chiral centers are different from each other di stemmers. Some of the chiral centers change and some of them are the same. So if we take a look here, we have two K centers here and here. And if we look right next to it, we have this structure which has two car centers as well. The OHS are on the opposite side. If you were to imagine a mirror was here and this was to look into the mirror, it would see this structure here as its reflection. So they are mirror images of each other. They are Inan tumors. Then if we compare, let's say that this is structure A, we'll say this is B, let's say this is C and then let's say this one over here is D if we compared A to C, what do we recognize? We recognize here that this Carl center, the O which is on the right, this Carl center, the O which is still on the right. They're the same. But if we look at the second Carol Center, the witches are on different sides. So one chiral center stayed the same one changed, they would be dier of each other. Then if we look at C and D, imagine there's a mirror here. This looks into the mirror, it would see D as its reflection. So these two are in an tumors of each other. Again, anatom are mirror images of each other. Meaning their chiral centers are the opposite at all chiral centers between each other. Dire stemmers are non mirror images. They're still sterile isomers. That just means that if you're comparing two structures in both structures, some of the chiral centers will be the same, some will be different. Now connected to this is the number of stereo isomers. And that's the formula two to the N where N equals our number of chiral centers. So if we take a look here, let's say we're looking at structure A and they only gave me structure A and they asked how many possible stereo isomers exist from structure A, it has two chiral centers. So it'd be two to the two, which would mean that we have a possibility of four stereo isomers, which is what we see, we see ABC and D four different sterile isomers from the fact that structure A had two chiral centers to begin with, right. So just keep this in mind when we're talking about anatom versus di starers and trying to determine the total number of sterile isomers.

Enantiomers vs Diastereomers Example 1

Circle all chiral centers in the following mono sac ride and state the number of possible stereo isomers. So remember a chiral center is where we have a carbon connected to four different groups. If we're to take a look here, our chiral centers would be one, 23 chiral centers. And we know that those are the chiral centers because those are the carbons connected to four different groups. This carbon here is not a chiral center because it is forming a double bond. So it can't make four individual single bonds. This carbon here is connected to two hydrogens. So it can't have four different groups and same with this one. So again, we have three call centers here. And the number of possible stereo isomers is based on the formula two to the end or N is the number of chiral centers. So this will be two to the three, which is two times two times two, which means we have a total of eight possible sterile isomers from this original mono sac ride. So those will be our two answers three chiral centers with a possibility of eight total sterile isomers

Identify each pair of carbohydrates as enantiomers or diastereomers.

• A. diastereomer, enantiomer 
• B. enantiomer, diastereomer 
• C. enantiomer, enantiomer 
• D. diastereomer, diastereomer

Draw the enantiomer of given structure of Xylose, and identify as D or L.

• A.
• B.
• C.
• D.