Give a systematic (IUPAC) name for each diol
(d)

Question

Give a systematic (IUPAC) name for each diol

(d) Chemical structure of a diol with two hydroxyl (OH) groups attached to a carbon chain.

(e) Structural representation of a diol with hydroxyl groups attached to a square-shaped carbon framework.

Accepted Answer

All right. Hi, everyone. So this question is asking us what are the systematic names of the following stereo isomers and to use Cyran designation. Here we have two dials. Now, first and foremost, the reason why both of these compounds are referred to as dials is because because we have two hydroxy groups within the same parent chain. So now let's talk about Iupac nomenclature in general, but also specifically for alcohols, our first step should always be to locate the parent chain. Now, the par chain is the longest continuous chain of carbons that contains our primary functional group, which in this case is the hydroxy group. So after locating the parent chain, it's always best to number the carbons of that chain so that the hydroxy group or groups plural have the smallest number possible on the parent chain. So you would find the parent name based on the number of carbons and also different modifiers to specify which functional groups are present from there, you would go ahead and identify and name any substituents branching off of the parrot chain and list them in alphabetical order before the parent name. So with this in mind, let's consider carbon number one or excuse me molecule. Number one. In this case, the longest continuous chain of carbons is a six member ring that contains both hydroxy groups present. Recall it normally speaking, a six member ring would be referred to as cyclohexane. However, because this molecule is not a simple cycle or can we have to modify the suffix based on what functional groups are present? But before we do that, let's go ahead and number the carbons of the ring. Now, in this case, it just so happens and you can, you can make either hydroxy group on carbon number one of the ring. However, because an akin, a double bond is also present within the ring, I'm going to go ahead and continue numbering my carbons in a counterclockwise direction to make sure the double bond has relatively small position numbers as well. It's important to go ahead and number the carbon chain because it helps us specifically identify where substituents are located. So here let's go ahead and introduce are modifier based on the presence of two hydroxy groups in this compound. Now, normally the e at the very end of Cyclohexane would have been dropped and replaced with an OL. However, here we have a dial, but what I'm also going to do is separate my modifier from the rest of the parrot name using the position numbers of those hydroxy groups, which would be one comma four dash dial. Notice how I'm separating numbers from letters using a dash and I'm using a comma to separate numbers from each other. But these aren't the only modifiers I have to put in, right, because we do have it keen present in this compound as well. So the A N Cyclohexane 14 dial must also be dropped and replaced with something else based on the presence of that double wand. So here instead of saying cyclohexane, I would say cyclohexane. And when I go ahead and specify the first carbon of the double bond, this becomes cyclo two in. So when I combine everything together, I get cyclo he two in 14 dial, but I am missing the CIS trans designation. So let's go ahead and finish off part one, recall that the cis configuration describes substituents that are not hydrogen being on the same side of the ring. In this case, on the other hand, substituents are considered trans when they are on opposite sides. So here we can see that the hydroxy group on carbon one is depicted on a dash going behind the ring or rather underneath underneath the ring. And the one on carbon number four is depicted on a wedge pointing towards us in front. So because of this, they, they are on opposite sides of the ring, which means that this is the trans isomer. So for part one, here, I have trans cyclo he two E 14 dial. And this time, I am also using a dash to separate the designation from the rest of the Iupac name. So now let's talk about number two. Now, in this case, for compound number two, we have only a six member ring as our parent chain with no double wants. So like we talked about in the first part, this would normally be referred to as Cyclohexane. However, a modifier should be added after this to specify the presence of these two hydroxy groups. So when numbering my parent chain, I can place the hydroxyl groups on carbons, one and two respectively. So at this point, what I can do now after the word Cyclohexane, I can add a dash place the position numbers of my hydroxy groups and then add the modifier dial. So that gives me Sacro Hexane one to dial as of this point. But once again, we should always make sure to add our cyst trans designation. So it just so happens that both hydroxy groups are depicted on a wedge, which means that both of them are pointing on the same side of the ring. This means that this is the cis iser and I would separate my designation from the rest of the, of the systematic name with a dash giving me cis cyclohexane 12 dial and there you have it. So here are the final answers for both compounds. However, what I do want to point out here is that position numbers can also be written before the parent name as opposed to within the parent name. So there are multiple ways of conveying the same information. But with that being said, thank you very much for watching and I hope you found this helpful.

Give a systematic (IUPAC) name for each diol
(d)
(e)

Key Concepts

IUPAC Nomenclature

Diols

Functional Groups

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