A little "gem" I wrote most of in my first year of uni, regarding the formation of carbonyl hydrates. It's still not quite accurate now, so don't take the mechanism as gospel!
1,1-Diol
My supervisor said to me,
"You say you understand this chemistry.
Well just to make sure, I think that I'll
Ask you this question about carbonyls:
"What happens to an aldehyde or a ketone
When you put it into water with a trace of base?"
He just looked into my eyes -
I got scared, I panicked
Until I remembered that all you get is a 1,1-diol.
Chorus:
Take the lone pair from water and attack the electrophilic carbonyl
It's no longer sp2;
Then recall water acts like a base, not like a nucleophile,
Deprotonates that water group;
Transfer the H+ to the oxyanion
And then all you get is a 1,1-diol!
What factors affect the position
Of this dynamic equilibrium?
As with most things I'd have to say
That steric factors can't be far away.
You increase the crowding round the carbon
As you move from sp2 to sp3 geometry.
Larger R groups disfavour that
And that's why you'll find that aldehydes are more likely to form a 1,1-diol.
Chorus
My my but you break that C=O pi bond, whoa whoa!
No no, but it's only for a while, it's an equilibrium.
As long as the pH ain't too low,
The Cannizzaro or aldol won't go so
Extract to organic, wash, dry, filter, strip...
No more diol.
[Dance break with balalaika]
Chorus
(Lyrics 2007 copyright of tze100)
1,1-Diol
My supervisor said to me,
"You say you understand this chemistry.
Well just to make sure, I think that I'll
Ask you this question about carbonyls:
"What happens to an aldehyde or a ketone
When you put it into water with a trace of base?"
He just looked into my eyes -
I got scared, I panicked
Until I remembered that all you get is a 1,1-diol.
Chorus:
Take the lone pair from water and attack the electrophilic carbonyl
It's no longer sp2;
Then recall water acts like a base, not like a nucleophile,
Deprotonates that water group;
Transfer the H+ to the oxyanion
And then all you get is a 1,1-diol!
What factors affect the position
Of this dynamic equilibrium?
As with most things I'd have to say
That steric factors can't be far away.
You increase the crowding round the carbon
As you move from sp2 to sp3 geometry.
Larger R groups disfavour that
And that's why you'll find that aldehydes are more likely to form a 1,1-diol.
Chorus
My my but you break that C=O pi bond, whoa whoa!
No no, but it's only for a while, it's an equilibrium.
As long as the pH ain't too low,
The Cannizzaro or aldol won't go so
Extract to organic, wash, dry, filter, strip...
No more diol.
[Dance break with balalaika]
Chorus
(Lyrics 2007 copyright of tze100)