Strong Bases for E2???

[GoBlue24]

This may sound like a dumb question but can you use the typical strong bases (NaOH, KOH) in E2 reactions?

For example, in a DATqvault question, it says you can't use NaOH for E2 reactions because "although sodium hydroxide is a strong base, it is also a good nucleophile and will produce an alcohol product via substitution instead of the desired alkene." Is this true? I thought even the strongest bases would do E2, according to Chad?

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[bluesolic]

This may sound like a dumb question but can you use the typical strong bases (NaOH, KOH) in E2 reactions?

For example, in a DATqvault question, it says you can't use NaOH for E2 reactions because "although sodium hydroxide is a strong base, it is also a good nucleophile and will produce an alcohol product via substitution instead of the desired alkene." Is this true? I thought even the strongest bases would do E2, according to Chad?

I need to see the question though, ( I assume that there is no heat or RT, or it uses aprotic solvent , IF the answer is SN2 )


The reason is little complicated,

First OH- is base/nuc,

so, it will use its basicity when it is all surrounded by protic solvent because the solvent slows the nuc so it will be E2

-> protic solvent also stabilize basicity too but for SN2, rate is really important factor so as long as protic solvent interrupt the nuc, SN2 power will significantly be decrease whereas, even though protic solvent interrupt the basicity, E2 work better.


also, high temp also favors it E2 because the hydrogen attached at the target molecule becomes more acidic ( easy to rxn with OH- -> E2 )




so, I assume that your problem may not mention heat, and it may mention that the solvent is aprotic solvent or it is primary good leaving group attached

RT w/ aprotic solvent, SN2 is almost 90% because the rate of SN2 is much faster than E2.