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Do both elimination reactions, E1 and E2, follow Zaitsev’s rule?

Answer 1

#"E1"# eliminations follow Zaitsev's rule. With two exceptions, #"E2"# reactions also follow Zaitsev's Rule.

(1) Certain cyclohexane derivatives.

Some cyclohexane derivatives, such as menthyl chloride, form the Hofmann product instead:

(from en.wikipedia.org)

But there is an antiperiplanar hydrogen at the 6-position, so elimination occurs there and produces only the Hofmann product.

(2) Bulky bases

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Answer 2

Nicholas Antonuccio

Yes, both E1 and E2 elimination reactions follow Zaitsev's rule. According to Zaitsev's rule, the major product of an elimination reaction is the most substituted alkene, which is the alkene with the greatest number of alkyl substituents on the doubly bonded carbons. This preference for the more substituted alkene is observed in both E1 and E2 reactions.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.