00:01
In this problem, we're looking at how many shifts we would expect given two different structures for proton nmr.
00:08
So your first one is a ketone, and you're asked how many peaks or signals you would expect.
00:19
So with proton nmr, you get different shifts based on the chemical environment.
00:26
So in this problem, each carbon here with hydrogens has a slightly different environment.
00:39
So typically our methyl groups, if it's near other carbons, which this one is, it's going to show up around 0 .9.
00:50
But these ch2s, even though both have two carbons, one is closer to our carbonyl, and our carbonyl pulls electron density towards it, so this one is going to be further downfield than this one.
01:12
And this ch3 is different from this ch3 because it's next to the carbonyl...