00:02
Okay, so one way we can go about answering this question is to, well, first let me redraw the fissure project or the online diagram.
00:14
Okay, so we've got a wedge here to oh, okay, we've got a dash here to oh, a dash here to oh, a dash here to oh, and a dash here to oh, great.
00:37
Now, one way we can go about this is we can just figure out what the absolute configuration of each of these stereo centers is.
00:46
And then pick a fisher projection or develop a fisher projection that will match this same configuration, right? so if we have a wedge to oh, right, oh, h is going to be our highest priority.
00:59
Second highest priority is the carbon with an oh, and methyl would be third.
01:03
Hydrogen is them in the back in this case, right? so this would be counterclockwise, which would make this first one, s.
01:13
Okay, but we know we've got an s here.
01:18
So that's how we can go about this.
01:19
Ok, next we say ok, oh is highest priority.
01:22
Then the carbon that's got two ohs over here is going to be higher priority than this one.
01:26
So this is three.
01:28
And this is clockwise.
01:31
But in this case, since we have hydrogen in the front, right? clockwise isn't r.
01:38
It's s.
01:39
We have to reverse it, right? because for example, if we put, if we swapped hydrogen in oh, it would look like it's r.
01:48
But we would swap.
01:51
And so we know it's the opposite, an antimer from that, right? so the second one is also s.
01:59
And then we can do the same thing here.
02:01
Highest priority, second highest priority, third highest priority.
02:04
It looks like it's going to be clockwise, right? but hydrogen is in the front, not in the back.
02:10
Right? so it's actually the opposite.
02:12
It's counterclockwise.
02:13
It means this one is also s.
02:16
And then finally, once again, highest priority, second highest priority, third, looks counterclockwise, except for hydrogen's in the front, not in the back.
02:27
All right, so you have to reverse it, and that means that this is clockwise.
02:31
So the final one is actually r.
02:35
So we have s, s, s, r.
02:39
Okay.
02:40
Now how do we interpret this? so let's make our fisher projection, right? so this is the ch3 at the end.
02:50
Okay, and this carbon, will be this card.
02:55
Right.
02:56
So if we wanted to make this s, well, let's put the rest of these in here.
03:03
Okay.
03:04
Right...