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.

Draw the product of each of the following reactions:

1.

Show how you might synthesize the following compounds, using acetylene and any ­suitable alkyl halides as your starting materials. If the compound given cannot be ­synthesized by this method, explain why.

d. 4-methylhex-2-yne

e. 5-methylhex-2-yne

f. cyclodecyne

Show how the following compounds can be prepared, using ethyne as one of the starting materials:

3. 2-methyl-3-hexyn-2-ol

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

Using the given starting material, any necessary inorganic reagents and catalysts, and any carbon-containing compounds with no more than three carbons, indicate how each of the following compounds can be prepared:

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)

Show how you would accomplish the following synthetic transformations. Show all intermediates.

c. but-1-yne → oct-3-yne