2,2,3,3-Tetrabromopentane can be prepared by an addition react...

Question

2,2,3,3-Tetrabromopentane can be prepared by an addition reaction of excess Br2 with an alkyne. Draw the structure of the alkyne and name it.

Accepted Answer

All right. Hi, everyone. So this question says, if an addition reaction involving excess co two with an all kind produces 3344 tetra Chloro Hexane provide the all kind structure and its name. So the first thing I want to do here is go ahead and actually draw our product, right? Our 3344 tetra chloral exane, our product in this case is a six carbon parent chain with a total of four chlorine atoms attached to it, right? So two of them are on carbon three of the perry chain and the other two are on carbon four of the parent chain. So now this he lied was the product of a reaction involving elemental chlorine or cl two in excess as well as an all kind. Now recall that all kinds are hydrocarbon molecules with carbon, carbon tural bonds. So before we get into the specific reaction that we're dealing with here, I want to point a few things out because sometimes an all kind reaction can be familiar to or similar to allen reactions. So first, let me discuss a similar reaction involving all keen, specifically, we can talk about the halogen generation of an old king. So if I take my all keen here with a carbon carbon double bond, and I react this with, well, not specifically chlorine, right, any halogen. So X two, then what happens here is that each halogen atom attaches itself to each carbon of the double bond. So I end up with a molecule that has two halogen atoms on adjacent carbon. So the reason why I'm bringing this up now is because with all kinds, it's a similar halogen nation process. But when there is an excess of halogen, then the same addition can happen twice, right? So if I take an all kind here with a triple wand and I react this with one mole of halogen, then I'm going to end up with two halogen atoms on adjacent cartin, right? But I'm still going to have a double bond in between my two carbons here. So when there is an excess of halogen present, then addition can happen twice, right? So two more carbons or two more halogens, excuse me, can add on to both carbons of the starting all kind. So that is exactly what's happening here, right? Because I have too much, but because I have four chlorine atoms on two adjacent carbons, then those two carbons must have had a triple bond in between them. So for the identity of the all kind, right, it's still going to be a six carbon chain, but there will be a double bond in between or triple bond, excuse me, in between carbon three and four. So there you have it. So now with respect to the name, right, this is a six carbon pairing chain, right? So the base name would be hexane, but because there is a triple bond in this molecule, the suffix A&E gets replaced with Y and E. So that's heck sign, right? However, I still have to specify where the triple bond is. So because the triple bond is in between carbons three and four, I would use the smaller number in my Iupac name and I can do so in between the prefix XX and the suffix Yne. So that is hex dash three dash I with dashes to separate numbers from letters and there you have it. If I scroll up one more time, then the achy required to produce 3344 Tetra Chloro exane from an excess of CL two was hex three in. So with that being said, thank you so very much for watching and I hope you found this helpful.

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2,2,3,3-Tetrabromopentane can be prepared by an addition reaction of excess Br2 with an alkyne. Draw the structure of the alkyne and name it.

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