From: Manuel Toennis (Manuel.Toennis$##$ch.tum.de)
Date: Tue Apr 20 1999 - 12:48:00 EDT
> C1-O-CH2-N(CH2CH2NHP)CH2-C2.
> I believe the ether link will be susceptible to acidic
> deprotection,resulting in the reformation of the phenol.
Aminoacetales are VERY sensitive to acids, but maybe the ring
stabilizes the compounds somewhat.
> I an also considering the same reaction method with a hydroxyamine
> (ethanolamine etc) as such a protecting group that is also selective for
> primary alcohols over amines would be ideal.
>
> I have in mind Fmoc, as it can be removed under mild conditions, but I
> would be grateful for any input from somebody with experimental experience
> in this area.
Dissolve your educt (diamine) - 2+ equiv. -
in water and add 1 equiv. Fmoc-Cl in Dioxane or THF slowly droppwise
with good stirring. The product precipates.
We use this method for Fmoc-hydrazine, but it also should work with
your substrates.
I'm rather sure that you don't need to protect your hydroxyamin- OH
group. The NH2 is much more reaktive, if your conditions aren't too
acidic. Therefor it would be very tricky to get an OH-protected
hydroxyamin (at least with one step), maybe then acryl-nitrile could
work as a baselabile PG. (R-O-CH2-CH2-CN, refer to DNA-synthesis)
But probably a good surplus of the diamine is enough to get only the
'monosubstituted' product.
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