命名烯烃-命名炔-概念

好的。我们将讨论烯烃和炔的命名。烯烃和炔是碳氢化合物的两种。烯烃含有双键，炔含有三键。

我们来谈谈命名。我从甲烷开始。我们知道冰毒只有一个碳。它是一个碳的前缀。如果你有一个碳它不可能是双键或者单键，或者三键连着另一个碳因为它只有一个碳，所以没有甲基。好，我们从乙烯开始。乙烯是双键，两个碳双键连在一起。丙烯或三个碳[IB]结合在一起或者是化合物中的什么双键。下面来看丁烯。丁烯的情况有点混乱。 The double bonds can be located in several different locations because there's four carbons. The double bonded can, the double bond can be between any of these carbons. If you get back to propene, if the double bond was here it's actually the same compound just flipped around. So the double bond in different places is okay. It's still propene. But let's look at butene a little more in depth.

如果我们回到我们的命名，我们的命名规则回到我们讨论烷烃的时候。我们学会了给母碳链编号。所以我们要给碳编号1、2、3、4。我们要命名它，我们会说双键在1号和2号碳之间所以它是1个丁烯。好的。很好。假设它在中间的两个碳之间。我们还是给它编号1 2 3 4我们把它叫做2丁烯这就告诉我们双键在2号碳之间而不是2号和3号碳之间。两个丁烯。

我们到这边来。假设它在最后两个碳之间也就是说我们叫它3丁烯。实际上，这和这一项是一样的。它翻转了，对吧?这里是一样的，只是转了个方向。所以这和1个丁烯是一样的。所以我要在它前面放一个1因为如果我要重命名，重新编号让它成为第一个碳，它实际上，你会注意到，这实际上是一样的。一，二，三，四。实际上，你想要的是最低碳之间的双键。所以你不会想要第三个键之间的双键，你会想要它在1号。 So you're going to have to renumber it to make it, make sure the double bond is between the lowest numbers, lowest number to carbons. Okay. so we'll get in this more detailed when we go into practice problems.

那么环烯烃呢，环上的烯烃呢，比如这个。我们知道这是戊烯。在每个交点之间你会看到，实际上你会看到它看起来没有碳但只是让你们知道，在这些点的每个交点上都有碳。注意这里有一个双键，所以我们要，两边都有甲基。所以我们叫它戊烯环。我还不打算给它命名，但这是一个戊烯环。这是5个碳，它们之间有一个双键。好的。我们来看看它们是如何分叉的就像我们讲戊烯上的分叉一样，有分叉脱落?所以我们有了父链和一些分支取代基。 So what I want to do is again just like how we name alkanes, we're going to number our carbons. So our first, our double bond gets the lowest number. So we notice the double bond is over here. so we're going to start nymbering our carbons from the left hand side to the right hand side. Okay? So I'm going to say this is carbon one, two, three, four, five, six, seven. Okay. So their number, number is going to be double bonds [IB] going to be between the second and the third carbon.

现在我们有了一些分支。这些是甲基。因为它们是，它们是两个，我们给它命名，它在6号和4号碳上。所以我们把它命名为4 6二甲基4 6，别忘了连字符二甲基2，这是庚烯。这是4 6二甲基2庚烯。这说明甲基在4号和6号碳上而双键庚烯说明它是一个双键碳。它在第二个位置。在第二和第三之间。这告诉了我所有需要知道的方向。我想，假设碳链上有不止一个双键。 So for example I have, and I didn't draw on the hydrogen just for a cumbersome reasons. I have this carbon chain, there are seven of them so I'm going to, it's going to be a prefix of hept beacuse that's a prefix for seven. You want to get your double bond at the lowest number as always. So let's say I number it this way, one, two, three, four, five, six, seven, going from left to right. My double bond's between the third and the fourth and then the fifth and the sixth. So I'm going to say three five heptadiene, the reason I use the prefix di, is because there are two double bonds there. If I had three double bonds within the carbon chain, it'd be triene, so and so forth. So this is three five heptadiene. Hepta means seven, di means two double bonds, ene means that [IB] that they are double bonds. Or it could look like this. This is the same exact chain except it's just flipped the other way. So this would give my carbon chain a double bond between the two and the four. So which would I like better? Three five heptadiene or two four heptadiene? This is actually the correct answer because it gives my numbers in the lowest, the lowest numbers of the double bond within the chain.

好的。让我们把这些都付诸实践。好的。假设我们有这个化合物。这有点复杂。我们要怎么给它命名呢?我要换一种颜色。我们选一个紫色的，我们要怎么给它命名呢?和往常一样，首先我们要弄清楚哪个是母碳链?父碳链必须包含这个双键。 So I'm going to have it start from down here. One, two, three, four, five, six, seven. Okay. We know it's a heptene. So because it has seven carbons. Hept is a prefix for seven ene is the suffix for double bond. So we know it's a heptene. Oops. Oh this pen is not working. Heptene. We know that double bond's between the third and fourth carbon. so we're going to say three heptene. Okay. so then we're going to talk about our branches. We have a methyl group here, we have a methyl group here and we have an ethyl group, two carbons, here. So we're going to deal for ethyl group first because our ethyl is group alphabetically it comes before methyl. E comes before m in the alphabet. So we're going to deal with, this is four. I'm actually going to do this. Four ethyl, four ethyl and this is three six, dimethyl, to show me that there are two methyl groups. And we said that was three heptene. This is the name of that compound. Notice I put the prefix di for two methyls. I had, the ethyl come before the methyl because alphabetically that make sense. There are seven hyd- there are seven carbons in there and the parent chain and it ends in [IB] telling me that there's a double bond in there.

好的。我们把这个画出来。我们有3 4二乙基1 6庚烯。yne告诉我有一个三键。没关系。三重键[IB]命名是完全一样的事情。它只是告诉你三键的位置而不是双键的位置完全一样。十七烯告诉我有七个碳3 4 5 6 7个。一，二，三，四，五，六，七。好的。 There is two triple bonds. So between the first and second and this last one. They're triple bonds telling me one's six and the diene tells me that they're two of them and the carbon three and four, because this is one, two, three, four, five, six, seven a carbon three and four, they are ethyl groups, which is two carbons. C C and [IB] C C. Alright? This is what your new this is what your structure will look like of this with this name, okay?

这些都是关于如何画碳，碳化合物的很好的说明。现在我要把剩下的都填满氢以确保它看起来是完整的。那么这里，有一个氢。别忘了每个碳都要4个键。这就是计算的方法。每个碳都要4个键。填满。把它们都填满就可以了。这是三,四。我知道如果氢有时候不画的话会有点乱。 It depends on what kind of structure yo do. But anyway the naming of the alkenes and alkynes it's actually pretty straight forward and it's basically math to draw, to figure out what the actual compound is.