00:01
In the mechanism of sodium borohydride reduction of carbonyl, and h -minus adds to the carbonyl carbon, which causes the carbon -oxygen pie bond to break with the electrons being localized on the more electronegative oxygen atom.
00:21
And then that anionic oxygen pulls off a proton from the surroundings and becomes an alcohol.
00:31
So for a, the hydride can come from either side, which means we would expect mirror image structures, but in this case, the structure is symmetrical.
01:22
So the mirror images are actually identical compounds.
01:31
Compounds, so we just get one product in that first example.
01:50
In b, we can get two products which differ in kind of the axial equatorial orientation of the alcohol group.
02:25
Now, c, sodium borohydride only reduces the ketone.
02:45
And the structure is more or less symmetrical.
02:51
So we're not specifically getting chiro isomers, but we do need to consider if the hydroxy group that's forming and the ester group are cis to each other or trans to each other.
03:52
Now, d, we're told to assume only one equivalent of hydride ads.
04:27
So we have two possible products.
04:48
Now, with the last three, we're dealing with some isotopic replacements.
04:54
So here's where thinking about the mechanism helps.
04:59
So if we have deuterium on the borough hydride, making it boroduduride...