Mark the chiral centers in the following molecules, if any, with an asterisk (*):

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   Ritalin®

Video transcript

Welcome back, everyone indicate if any carol centers are present in the compound shown below if present labeled using an asterisk. So we are focusing on chiral centers and specifically for this problem, we are focusing on the carbon atoms that have four different substituents bonded to them. Now, what we're going to do in this problem is simply skip all of the hetero atoms, specifically oxygen, sulfur and nitrogen. We're only going to focus on carbon. So let's do that. First of all, the we first carbon that we see. Well, it is basically within the carbonel and carbonel. It has three substituents, oxygen oxygen in another carbon. So it cannot be chiral, right. So we are just going to put x it's not chiral. Then if we go down towards the rank, we can see that there is a carbon atom that is bonded to nitrogen. That's our first substitute. We don't need to worry what else is bonded to nitrogen. On the left side, there is carbon. Now going up, we have another carbon but that carbon is different because it's carbon and not CH two. So that would be our third different substituent. And of course, the fourth bond is an implicit hydrogen atom. So indeed, we can see that there are four different substituents, right? Meaning that specific carbon is chiral and we can label it using an asterisk. So let's label that specific carbon as a chiral carbon atom. Now, when we consider the rain, we can see that we have multiple carbons with two bonds, 12 and three. And because those carbons have two bonds only, there are implicit two hydrogen atoms, meaning they are not chiral, right? And the reason why they are not coral is because they don't have four different substitutions, they have two exactly same hygen each. So we're simply going to not worry about any carbon atoms within the five member ring. Now, when we look at the side chain bonded to nitrogen, we have carbel, once again, it cannot be chiral because it only has three bonds, two single bonds in one double bond. So it doesn't have four single bonds, we can just skip it. And now we can clearly see that we have a potential candidate for chirality. There is carbon bonded to hydrogen, it is bonded to CH three a metal group, then it is bonded to CH two sh. So one of the hydrogen atoms is now replaced with sh this is definitely different from CH three. And on the left, we have Car Bono Ceo and we can clearly see that those four are different subscriptions, meaning we have detected an additional chiral center. So we're just marking it with an asterisk. So now let's clear everything and just consider the two carbon atoms that are remaining. So for the metal group, there are three exactly same hydrogen atoms, they are all the same. There are no four different subscriptions, meaning this specific carbon is not Cairo. And finally, as we already know, we have ch two, there are two implicit hydrants which makes the final carbon knot chiral as well. Since it doesn't contain four different subscriptions, it has two exactly same hydrant. So we only have two carbon atoms that are chiral in the structure and we have marked them. Thank you for watching.