Provide the IUPAC name for the following molecules.
(a)...

Question

Provide the IUPAC name for the following molecules.

(a) Chemical structure of a cyclopentane with a hydroxyl group, illustrating cis and trans isomerism.

Accepted Answer

Right. Hi, everyone. So first question, let's determine the system, the systemic name, excuse me of the structure below. So when determining the systemic name of a compound, my first step is usually to go ahead and determine my parent chain, right? And in this case, our parent chain is a ring. So we're going to be adding cyclo as a prefix to however many carbons we have in the chain. So here, what you'll notice is that we have a, a six member ring which indicates that our parent chain is going to be cyclohexane. And in addition to Cyclohexane, we have an O H group, right? So it is an alcohol derivative now because it's a ring, right? And we have to specify the positions of all substituent on the ring, we can say that the group is on position one in the ring because it is going to be the highest priority. So therefore I can modify my name a little bit and specify that it is going to be cyclo hex one. Oh Right. Because instead of saying cyclohexane, it should really be cyclo hexen because we do have an alcohol, right? And that alcohol is on position one. Now, in addition to the group, we do have one other substituent, right, we have a methyl group adjacent to carbon one. So therefore, to make sure that it has the smallest number possible, we're going to say that this methyl substituent is on carbon two. So therefore, before my parent name here, I have to specify any other substituent, which in this case is just the one me group on position two. So to recap, right, my preliminary name thus far is two methyl cyclohexane 10, but I'm not quite done, right? Because what you'll notice is that both carbons, one and two are actually stereo centers. And the reason I know they're stereo centers is because they have wedge and dash notation, right? So before I can finish off my systemic name, I have to actually specify whether or not each stereo center is R or S. So here, let's go ahead and recall the rules, right. My first step is to assign the priorities of all groups attached to my stereo centers. So here for carbon one, my O H group is going to have the highest priority because it is a hetero atom and therefore it has a higher atomic mass. So here, right, notice how carbon one is bound to two other carbons, right? So there's a tie there. And because of that, we have to consider what else each carbon is bound to. Now here one carbon is bound to the methyl group and another carbon in the ring, whereas the other is bound only to just one carbon and two hydrogens. So therefore, my carbon two is actually going to be second place because it is bound to more carbons as opposed to the other one and the other carbon therefore is third place, followed by the hydrogen that was not shown here as fourth place. Mhm. So you'll notice right when we're going in a circle from the highest priority to the lowest, what you'll notice is that we're doing so in a counter clockwise rotation with the lowest priority in the back, right, the hydrogen is in the back. So therefore, what that means is that carbon one is in the s configuration. So now let's go ahead and do the same thing with our other stereo center at carbon two. Now, carbon two has another hydrogen that has not been drawn, right? And because the metro group is a dash, our hydrogen has to be a wedge. So hydrogen is going to be the fourth highest priority or the lowest priority. And notice here that carbon two is bound to three other carbons. So just like in the first stereo center, we have to go ahead and consider what else they are bound to to kind of break the tie, so to speak, right. And what you'll notice is that carbon one is bound to another carbon, a hydrogen and oxygen, right? So because of that it is actually going to be the highest priority. And carbon three on the ring here is going to be the second highest priority because it is bound to one other carbon in addition to hydrogen, our Meho group, on the other hand, takes third place because it is only bound to three hydrogens. So now, mhm. So now when going in a circle from the highest priority to the lowest right, we are doing so oh to the er on the wrong color, but we're doing so in a clockwise rotation, but the lowest priority group is actually in the front. So we have to do the opposite, so to speak. And because the lowest priority group is in the front, then that means that stereo center two is actually in the S configuration and now we can complete our systematic name, right? So in parentheses, I'm going to specify my stereo centers and also their configurations separated by a dash, right? So I'm going to write in parentheses in order of appearance in the parent chain, one S comma two S and that is my complete answer, right? My final answer is going to be one S two S two methyl cyclohexane 10 and I know that's a mouthful. But if you stuck around to the end, thank you so much for watching. And I hope you found this helpful.

Provide the IUPAC name for the following molecules.
(a)

Key Concepts

IUPAC Nomenclature

Functional Groups

Cycloalkanes

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