Cyclopropane is an interesting hydrocarbon. Instead of having three carbons in a row, the three carbons form a ring, as shown in this perspective drawing (see Figure 2.18 for a prior example of this kind of drawing):

Cyclopropane was at one time used as an anesthetic, but its use was discontinued, in part because it is highly flammable. (b) The three carbon atoms are necessarily in a plane. What do the different wedges mean?

Video transcript

Welcome back everyone in this example, we're told that glucose is an interesting molecule. It can exist as an open chain molecule or as any of its four cyclic summers. One of its cyclic I summers is shown below And we need to figure out what the dashed bonds represent in our given structure. So let's recall that our formula for glucose is C6, H 12. And then 06. And as we are told from the prompt, what we have here shown to us is one of its cyclic summers and we know that it's a cyclic I summer because we should recall will have different arrangements and sorry, we'll use the black pen of substitute parents and they lack the ability of being a mirror image of the original compound or the other. I summers Now looking at are given structure here, we should recall that our ring is made up of carbons. So for each point would we have our first point here, we have a carbon here. And according to this bond, we have a substitute print on a dash where we have an oxygen bonded to a hydrogen atom. And that would be this carbon bonded to these two atoms here where it's also bonded to this carbon as well as this oxygen here. So just to fill these atoms in, we have a carbon here, a carbon here. A carbon here. A carbon here and a carbon here. And because this is a cyclic summer, we only have five carbons where in our original formula for glucose. In our original structure we would have six carbons but the cyclic summer replaces one of these carbons with this oxygen here. Now, in comparison we should observe that we have a a dashed line here. So here we have a dashed bond. And sorry, we'll just say well spell that again a dashed bond. And here we have a wedge bond and we'll use actually a different color. So this is our wedge bond. We also should recognize that we just have our standard bond here. And in terms of our standard bonds which are just regular drawn in lines, we would assume that are standard bonds are in our plane of the page or of the paper we can say. And so if we know that our standard bonds are going to be in our plane of our papers, we would say that therefore for our dash bonds, we would assume or recall that these mean that these bonds are out of the plane of the page. And so therefore they're behind our page. So if we were to imagine our three D structure, these bonds would be going behind the plane of our solid line bonds. And so that would leave us with our wedge bond, we can say that therefore our wedge bonds we should recall are going to be coming forward or we'll just say coming outward of the plane of the page or paper. And so therefore they're going to be in front. And so what this means is that for our final answer we can confirm that our dashed bonds represent that our substitue ints of the cyclic ice swimmer are behind the plane of the molecule. And so we want to highlight this part of our statement because this explains what the dash bonds represent in our molecule. And this would be something that we should recall as stereo chemistry. This is the stereo chemistry of each of our substitue ints making up this cyclic summer of glucose. So what's highlighted in yellow in our solution is our final answer. I hope that everything that I reviewed was clear. If you have any questions, please leave them down below and I will see everyone in the next practice video.