Least Substituted Elimination?

[jhanago]

I read somewhere on this site that an E2 elimination would favor the least substituted carbon, yet my textbook states otherwise...



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[bharat008]

I think that it's a typo. It should have been hoffman product or anti-zaitsev product.

Whenever you have a tertiary alkyl halide and a bulky base then you always form HOFFMAN product (least substituted)..

That's what i think.. Anyone else??

 

[jhanago]

I think that it's a typo. It should have been hoffman product or anti-zaitsev product.

Whenever you have a tertiary alkyl halide and a bulky base then you always form HOFFMAN product (least substituted)..

That's what i think.. Anyone else??

Problem is it's consistent throughout the whole book... even in sample problems and practice problems etc

 

[bharat008]

First of all, E2 doesn't favor least substituted product all the time. IT usually favors most substituted product, the only exception is when you have a bulky base and tertiary alkyl halide then you will get least substituted product.

Ex - tertiary alkyl halide + bulky base = least substituted
Primary/Secondary + Bulky base = most substituted..

 

[Bis-GMA111]

also make sure that it's anti peri planar

 

[yappy]

Good thought but it shows no stereochemistry. actually... in the rxn is there any chiral centers? I dont think that there is on the reactant side.

also make sure that it's anti peri planar