00:03
In this problem, we are shown two molecules, a and b, and told that b cyclizes to form a.
00:10
And the first question we're asked is which two functional groups on molecule b react with each other to form a, to make that cyclization happen.
00:20
So to figure this out, i'm going to kind of track it through the molecule.
00:24
So i'm going to start with this group right here because it's a very recognizable group on both.
00:31
So if we go up that wedge and one carbon over, up the wedge and one carbon over, on b we hit an amine, which we also see on a.
00:41
But then on b, we hit an alcohol, which on a is now part of that ring.
00:46
It's the o in that ring.
00:48
So it tells me that the oh over here is probably involved.
00:53
And then if we go the other direction from that wedge, we go one, two carbons, one, two carbons.
00:59
Then we hit a carbons.
01:00
Acid on both and then if we go one carbon up here on b we have an aldehyde and on a we have an alcohol so that means that this aldehyde was also probably involved in that cyclicalization reaction so what it looks like is happening here is this alcohol and the aldehyde are doing a nucleophilic addition reaction so this oh h is going to come in here and attack that carbonyl carbon which will push the pi electrons in that double bond onto the o, which is how the o here ends up connected to that carbonyl carbon or what used to be the carbonil carbon on b.
01:41
And this o from the aldehyde turns into an alcohol on a...