Draw skeletal structures for the compounds in Problem 3, includin...

Question

Draw skeletal structures for the compounds in Problem 3, including any cis–trans isomers.

Accepted Answer

Hey, everyone. And welcome back in this video. We're going to draw the skeletal structures of the cis and trans eyes. Members of the given structure. The given structure is CH three CH two CH ch ch ch 32 times looks like it's a bit complicated, but let's not worry about it. And let's try to expand it at least partially. So, first of all, we're going to draw three hydrogen atoms bonded to that first carbon atom which is bonded to see each too, which is bonded to CH. And now this is where we have our carbon carbon double bonds. We have another CH which is bonded to CH and that CH has two metal groups because they are indicated. And Francis with a subscript of two. So that's the structure that we have. And specifically, we are going to draw its bond line representation to do that. We are going to find our longest chain. Let's suppose that we start with this metal group and we go 1234, 56, we have six carbon atoms in the longest chain. So let's draw them 123456, we have six carbon atoms. And essentially, let's see if we go that way. 123, the double bond starts at position three. If we go the other way, 123, the double bond still starts at position three. So it doesn't matter how we enumerated. And we can essentially go from here that we carbon number 123, the double bond starts over here at carbon three and extends to carbon number four. And then we understand that at position two, we have a metal group. So 12, that's our carbon number two, we are going to add our metal group. So we have our skeletal structure. Let's see if that's right. We have 123456 carbon atoms. The double bond starts at carbon three and add carbon number two, we have a methyl group. Now this is actually trans eyes more. If you look at it carefully and the reason why it's a trans eyes mur, it's basically because if you look at your double bond and if you expand these implicit hydrogen, we are going to draw them in blue, the two hydrogen atoms are on opposite sides with respect to the double bond because they're on opposite sides, we call such an ism or trans because whenever you have an L keen, which has two, exactly same groups X and X on opposite sides with respect to your double bond, that's a trans eyes mur. And if you want to get sis you're just making sure that the two X groups are on the same side of the double bond. So that be sis, meaning if we want to turn it into sis, we're going to draw our double bond and we're going to rotate it even though actual rotation is not possible, right? It's basically restricted from rotation, but we're just going to swap our substitutions or for simplicity, let's just swap this hygiene and this ethyl substitution. So we are going to leave everything as it is on the left side. So now we have our hydrogen, which is actually can be shown as implicit, right? Because we want to make sure that we are dealing with tell el structures okay. And now we want to make sure that the ethyl group is pointing up so that the two hydrants are pointing down. And if we do that, we get the following, so notice how now the two implicit hydrogen are on the same side of the double bond. In other words, they're both below the double bond. While in the previous structure, one of the hodgins is below the double bond and another one is above the double bond. So the first structure was trans and the second structure is cece, we can eliminate the implicit hygiene Adams because we were asked to draw skeletal structure. So there's no necessity to show implicit hydrogen. We can just eliminate them and label these CIS trans eyes versus our final answers. Based on the identities of the structures. We can conclude that the correct answer to the multiple choice question is a thank you for watching.

Draw skeletal structures for the compounds in Problem 3, including any cis–trans isomers.

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