OK, last one are enantiomers. So here I'm going to do 2 -iodo- butane, again.
So what is that? 2 -iodo- butane.
So I got CH3, CHI, CH2, CH3. So I got four carbons.
That's my butane. And I bond--
maybe I should have written it like this, it's easier for you to see.
H and Iodine, to the second carbon. So that's my 2 -iodo- butane.
Now I'll look at that carbon and I'll try and draw it in
three dimensions again. So here's that carbon iodine bond sticking
out. That hydrogen is going to stick in.
And then I have to bond a methyl group to this, and then an ethyl residue.
Two carbons. Instead of using my finger I'll--
so that's sticking out. Now the importance of that is that imagine
taking a mirror-- Iodine, H in the back, and then CH3, and CH2,
CH3. And, of course--
and sort of building a reflection, and I know you know what I'm going to say
now is that this molecule cannot sit on top of that one.
They're mirror images. It's like your left hand and right hand.
And so we're going to pick up that next time.
