00:03
This is the answer to chapter 14, problem number 77 from the smith organic chemistry textbook.
00:12
And this problem asks us to explain why the carbon -13 nmr spectrum of three -methyl to butanol, which i've drawn here, why it shows five signals.
00:27
And so we might at first glance be tempted to say that these.
00:33
These two methyl groups here and here are equivalent, and so we would expect only four signals, since those two would give the same signal.
00:46
But if we redraw this molecule and just assign, so let's arbitrarily assign this alcohol, this stereochemistry, so we'll put the alcohol.
01:08
On the wedge and that hydrogen on the dash there.
01:13
So if we do that, and then we replace one of those two methyl groups, either one really, with something else, with x, you know, just a generic substituent, what we see is that we actually get a set of diastroids.
01:41
Stereomers.
01:43
So we've arbitrarily assigned this stereochemistry here to the alcohol.
01:47
And so we either get x that is cyst to that alcohol, or we get an x that is trans to the alcohol.
02:02
Just give me a moment to finish drawing here...