00:02
Okay, so this is chapter 12 problem number 16 from the smith organic chemistry textbook.
00:10
And this question is asking us to epoxidize three alkenes with mcpba, which we know forms an epoxide when an alken is treated with it.
00:23
And so for a, what we see is we get a set of an antimers when we treat a with mcpylus.
00:32
And so initially i've drawn the answer as attack from above yields this product, attack from below the alken.
00:45
If we picture the alkenes flat and horizontal in the plane of the whiteboard, the oxygen is adding from below.
00:55
And so to make it easier to see that these are anantiumers, i've basically just just it's rotated this 180 degrees around the carbon -carbon bond.
01:08
And when you do that, you see that they do just differ at this one position.
01:13
The methyl group here wedged, the methyl group here dashed.
01:19
And so the answer to be, and i apologize, looks like it didn't quite finish this.
01:31
So the answer to be, when you treat alkyne b with mcpba, you get this epoxide as the sole product.
01:45
And the reason that you get that as the sole product is because if you were to draw the product of oxygen adding from below, what you would get is this.
01:57
What i've drawn down here.
01:58
If you were to flip that horizontally, what you'd get, and i'll just draw it quickly...