Re: hydroboration

watanama@plu.edu
Thu, 05 Dec 1996 09:47:06 -0800 (PST)

I don't know if I can explain it better than the book, but I'll try.
Hydroboration IS anti-Markovnikov.
Anti-Markovniv, so that means that the hydrogen attaches to the carbon
with fewer hydrogen atoms. The boron attaches to the least substituted
carbon of the double bond. It does this because boron group is large and
needs the greater space to attach to the carbon molecule. In other words,
it tries to avoid steric hinderance.

The addition of boron to the less substituted carbon, forces the hydrogen
left from the THF:BH3 to be added to the other carbon which consequently
has less hydrogens because that carbon is the more substitued of the two.
Hope that all made sense! Good luck.

On Thu, 5 Dec 1996 SFCBIRD@aol.com wrote:

> Hey chemistry fans!
> I have another question.
> I still don't understand why hydroboration is anti-Markovnikov? I thought it
> is a Markovnikov. Could someone explain this more understandably than the
> book said?
> If any one can explain I would appreciate it.
>
> eunsan
>
>