From among the 18 constitutional isomers of C _{8}H_{18}, write structural formulas, and give the IUPAC names for those that are named as derivatives of

(d) Butane

Hey everyone. So, for this question in Part D we're going to be drawing and naming the butane derivative for the constitutional isomer of C8H18, okay? So, just keep in mind though that it has to be butane and that means that the longest great chain of carbons needs to be 1, 2, 3 and 4, so this could be a little bit tricky because we need to have C8H18 but here all we have is C4H10, so we need to add on four more carbons and eight more hydrogens and we need to keep our long and chain as a carbon, as four carbons what we're going to do is say we did something like that, in order to find out the longest chain we would go 1, 2, 3, 4 and 5, so this is no longer a butane. So, keep that in mind, we can only be adding on a carbon here a carbon here, right? to keep it butane, but you only have six carbons. Now, we need to add on two more, so we're going to add on another carbon there and another carbon here, so that we actually kept this as 1, 2, 3 and 4 is still butane, so let's go ahead and name it, we have 2,2,3,3 and now what do we call this? do we call it di-dimethyl? Well, no there's four carbons, we just call it tetramethyl, right? Same thing as if it was just two it would be di, if it was 3 it would be tri and so forth and we need to include that it's a butane, okay? So those are going to be the only actually derivative that's a butane root of C8H18 and what we've notice is that this is actually a constitutional isomer to this thing right here, because here we have 1, 2, 3, 4, 5, 6, 7, 8, this is C8H18 and so is this, this is also C8H18, okay because both of them follow the general formula of CnH to the two n plus 2, okay? So I hope this made sense and you're able realize that we had to keep our longest for a chain of carbons four to make it butane. Alright so, let me know if you have any questions.