9. Alkenes and Alkynes

What stereoisomers are obtained from the following reactions?

The following reaction was recently reported to have been performed electrochemically.

(a) Identify the reagent and a solvent that could have been used if this reaction was done traditionally.

(b) What safety and environmental hazards are improved or worsened when doing this reaction electrochemically?

For the alkynes shows here, show the product(s) expected to form when treated under the following conditions: (i) H₂ , Pd/C; If you expect two products, show both.

(c)

For the alkynes shows here, show the product(s) expected to form when treated under the following conditions: (ii) H₂, Pd/C, Pb(OAc)₂ , CaCO₃ (Lindlar's catalyst). If you expect two products, show both.

(c)

For the alkynes shows here, show the product(s) expected to form when treated under the following conditions: (iii) Na⁰ , NH₃ (liquid), ―33°C . If you expect two products, show both.

(c)

Predict the product of the following alkyne reductions.

(a)

Predict the product of the following alkyne reductions.

(b)

Predict the product of the following alkyne reductions.

(c)

Suggest alkynes that might be used to make the following trans-alkenes.

(a)

Suggest alkynes that might be used to make the following trans-alkenes.

(b)

Suggest alkynes that might be used to make the following trans-alkenes.

(c)

When sodium generates electrons in the presence of ammonia, these electrons persist in solution, giving the blue color. However, electrons do not persist when sodium is added to water. Why?

Predict the product of the following hydrogenation reactions run with a poisoned catalyst.

(a)

Predict the product of the following hydrogenation reactions run with a poisoned catalyst.

(b)

Predict the product of the following hydrogenation reactions run with a poisoned catalyst.

(c)