i wonder what would happen if you were to attempt the reaction on the alcohol but with a longer chain between the -OH and the -Br, and 2+ equivalents of NaH.
I'd bet you're deprotonating the alcohol and making the epoxide there. Even though the ring is strained, the intramolecular effect makes this a pretty fast, and probably competitive reaction.
While the epoxide might still be a decent electrophile, there's no base left to deprotonate the amide to make it nucleophilic. Also, depending on the conditions it might be escaping as a gas.
In my opinion, the best suggestion to get around it is exactly what you did - use a protected alcohol.
8 comments:
Think you might have been deprotonating the alcohol?
So what? a protonated alcohol will stop the reaction?
Dunno. Did nothing happen at all, or did you get crazy side products?
(I'm a mediocre organiker at best, which is why I stick to materials ;) )
i wonder what would happen if you were to attempt the reaction on the alcohol but with a longer chain between the -OH and the -Br, and 2+ equivalents of NaH.
To: Ψ*Ψ
No rxn at all.
st recovered after 24 hr.
to: stokes_brolandish
this kind of rxn actually presented in some literature, they just use a unprotected alcohol and they got a decent yield.
I'd bet you're deprotonating the alcohol and making the epoxide there. Even though the ring is strained, the intramolecular effect makes this a pretty fast, and probably competitive reaction.
While the epoxide might still be a decent electrophile, there's no base left to deprotonate the amide to make it nucleophilic. Also, depending on the conditions it might be escaping as a gas.
In my opinion, the best suggestion to get around it is exactly what you did - use a protected alcohol.
To Russ
you may be right.
thank you for your comment.
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