9. Alkenes and Alkynes

A student provided the product of the following reactions, but made a mistake. Identify the mistake, correct the mistake, and suggest a way for the student to avoid that mistake in the future.

(a)

Suggest reagents you might use to generate the product from the given reactant.

(c)

Suggest a method for synthesizing the following alkynes using an alkyne and an alkyl halide. [There are two correct answers for each product.]

(a)

Why is a cumulated diene not formed in the reaction shown above?

A chemist attempted to do the following acetylide alkylation reaction but was unsuccessful in several attempts, producing only the original starting materials in each case. Explain why the reaction didn't work.

What is the major product of the reaction of 1 mol of propyne with each of the following reagents?

j. the product of part i followed by 1-chloropropane