9. Alkenes and Alkynes

What is the major elimination product obtained from an E2 reaction of each of the following alkyl halides with hydroxide ion?

f.

When 2-bromo-3-phenylbutane is treated with sodium methoxide, two alkenes result (by E2 elimination). The Zaitsev product predominates.

a. Draw the reaction, showing the major and minor products.

What is the major elimination product obtained from the reaction of each of the following alkyl halides with hydroxide ion?

c.

Predict the major product(s) of the following elimination reactions, paying close attention to the stereochemical outcome of the reactions.

(b) 

Which of the following alkenes is the major product according to the $\mathrm{Zaitsev}$ rule in the $E2$ dehydrohalogenation of $2-\mathrm{bromobutane}$?

Draw the elimination products for each of the following E2 reactions; if the products can exist as stereoisomers, indicate which stereoisomers are obtained.

d. (2R,3R)-2-chloro-3-methylpentane + high concentration of CH₃O^-

Which alkyl halide in each pair is more reactive in an E2 reaction with hydroxide ion?

c.

d.

Using Zaitsev's rule, which of the following alkenes is expected to be the most stable product in an elimination reaction?

Which of the following alkenes is the major (Zaitsev) product formed in the E2 dehydrohalogenation of $C_3{H}_7\mathrm{Br}$ (2-bromopropane) with a strong base?

What is the major product formed when the following compounds undergo an E1 reaction?

c.

Predict the major product(s) of the following elimination reactions, paying close attention to the stereochemical outcome of the reactions.

(c)

For each of the following reactions, draw the major elimination product; if the product can exist as stereoisomers, indicate which stereoisomer is obtained in greater yield.

e. 3-bromo-3-methylpentane + high concentration of CH₃CH₂O⁻

f. 3-bromo-3-methylpentane + CH₃CH2OH

What products will be obtained from the E2 reaction of the following alkyl halides?

b.

For each of the following compounds, draw the product that forms in an E2 reaction and indicate its configuration:

a. (1S,2S)-1-bromo-1,2-diphenylpropane

For each of the following alkyl halides, indicate the stereoisomer that would be obtained in greatest yield in an E2 reaction.

c. 3-bromo-2,3-dimethylpentane

d. 3-bromo-3,4-dimethylhexane