North American termite soldiers, when encountering enemy insec...

Question

North American termite soldiers, when encountering enemy insects, contract their mandibular muscles, expelling a mixture of chemicals that essentially trap their enemies in a glue-like substance. This weapon, built into the face of the termite, is called the fontanellar gun. It releases a mixture of pinene (62%), myrcene (27%), and limonene (11%). pinene myrcene limonene 62% 27% 11%

(a) Identify the isoprene units in pinene, myrcene, and limonene.

(a) Identify the isoprene units in pinene, myrcene, and limonene.

Accepted Answer

All right. Hi everyone. So for this question, let's go ahead and determine the isoprene units of the given Turpin. And the turbines in question are beta thine retinol and gamma Turpin. So first and foremost, let's go ahead and introduce the isoprene rule for this question, right? Because the isoprene rule states that there are three predominant ways in which isoprene units combine to form turbines. The first of which is going to be head to tail linkage or 1 to linkage. The second method is tail to tail linkage or 4 to linkage. And the third method is head to head linkage or 1 to linkage. Now, at times what you'll notice is that especially with turbines that contain ring structures, there are going to be linkages that are not between carbon one or carbon four of the isoprene unit itself. Now recall that the isoprene unit is a four carbon chain with a methyl substituent on carbon tube. So this is going to be the backbone structure that we're looking for when analyzing the structure of these chirping, right. So what I'm going to do now is I'm going to label carbons one through four of the parent chain. But the methyl group on carbon two is going to be labeled number five. And now let's start with analyzing our beta through gene here. Now, in order to be able to understand the structure of beta through gene a little bit better, I went ahead and I redrew it on the bottom of the screen. Now here, when it comes to analyzing the structure of a urine to figure out the isoprene units, the easiest thing to do is to determine where carbon five is for each unit. And by carbon five, I'm referring to the methyl carbon on position two because what I'll notice first and foremost, right is that here, I have two methyl substitutes in this molecule. So that's going to be my carbon five for my two isoprene units that I'm going to have here. And carbon five I know is going to be connected to carbon two, right? So from there, I've figured out my parrot chain for each unit and there you go. So now by doing this right, I've gone ahead and I've realized that I'm going to have two isoprene units in the structure of beta ji. So now I'm just boxing them together so you can see them better. So here is beau and now let's go ahead and scroll upwards to understand or analyze the structure of retinol. And like I said before, the easiest thing to do here is analyze where your Meho groups for each isoprene unit are. And what you'll notice here about retinol is that here, we have a total of four methyl groups, 123 and four metal groups. Now, it's another thing or it's also worth noting that when it comes to analyzing the number of isoprene units, you should go ahead and, and ignore all functional groups like the hydroxy group here in retinal, we know it's there, right? But we're not going to be analyzing it as part of the isoprene unit because it's not. So now I can go ahead and figure out where my carbon two is going to be for each subunit. And from there, I can gather the rest of my parent chain and I can go ahead and separate these units from each other. The nice thing about retinol is that here we have multiple isoprene units being connected together, right? So as soon as I finish labeling the fourth carbon of one unit, I know the next one over is going to be the first carbon of the second unit and so on. So now I can go ahead and label all of my isoprene units. So what you'll notice here is that the ring structure of retinol is made up of two isoprene units because you can essentially cut the structure in half or not in half, but you can at least cut the ring into two parts. He's the third unit. And like I said before, right, three of our units are connected together via a straight line. So in this case, it was a little bit easier to kind of tell where one unit ended and the other began. And lastly, let's go ahead and talk about gamma TNI because gamma urine similar to beta through gene has two distinct met groups that I can go ahead and circle. So once I do that right, I've identified my carbon five for each unit. And then from there, I can figure out my carbon too by looking at the carbon that number five is connected to. And then from there, I've gathered the rest of my parenting and just like beta through gene, right? I have, I have two isoprene units in the structure of gamma urine and there you have it. So here is your final answer. Retinol had a total of four isoprene units, beta gamma urine, excuse me, had a total of two isoprene units and beta through gene also had two isoprene units. So here if you stuck around to the end, thank you so much for watching. And I hope you found this helpful.

Key Concepts

Isoprene Units

Terpene Structure

Chemical Composition and Percentages

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