alkyl halide into alkene?

[BiomajorPreDent]

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How can you convert an alkyl halide into a high yield of alkene??

 

[PooyaH]

You can make alkenes from alkyl halides through elimination!!!

 

[BiomajorPreDent]

right, I should have been more specific im sorry.

I meant, how do you make a large yield of the alkene? Does the elimination have to occur at a certain carbon or something?

 

[PooyaH]

right, I should have been more specific im sorry.

I meant, how do you make a large yield of the alkene? Does the elimination have to occur at a certain carbon or something?

Yes, the compound has to have the right conditions for E1 or E2 to occur. That's the only method I know for the formation of alkenes from alkyl halides!

 

[achytooth]

There's alot too this question then,

Is the reaction in a base, or a acid. Is it a strong base? a bulky base?
protic/aprotic solvents?

is the alkyl halide primary?

Is it tertiary?

A large yield, I'm guessing would probably be a tertiary alkyl halide via one of the eliminations so you dont have competition for substitution.

 

[BiomajorPreDent]

ahh sorry, Im pretty sure acidic conditions...I am going from memory..tertiary..that makes sense though

 

[pbure9]

you can have a secondary with a base like OH- or something that'll go Zaitsev. Or a bulky nuc that'll go Hoffman E2. You can also have it on a tertiary and do E1, but you may get some SN1 too

 

[tdkyun]

you'll need a pretty strong base to pluck off a hydrogen for E2.
And also a bulky strong base like tert-butoxide will get you a terminal alkene.
For E2, there must be a hydrogen present that is anti-periplanar to the halide.
hmm what else? I must think.
Polar protic solvent will help to stabilize carbocation during E1