9. Alkenes and Alkynes

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

f. cyclodecyne → cis-cyclodecene

Identify the product when each of the following reactions is performed on the triglyceride of linoleic acid (linoleate).

(a) H₂ , Pd

Predict the product of the following alkyne reductions.

(b)

What stereoisomers are obtained from the following reactions?

Hydrogenation of which alkynes would produce the following cis-alkenes?

(c)

Sodium amide, the base we use to deprotonate terminal alkynes, is synthesized by reducing ammonia via a mechanism similar to the reduction of alkynes in Figure 10.21. Suggest a mechanism for this reaction.

Describe the alkyne you should start with and the reagents you should use if you want to synthesize

c. trans-2-pentene.

d. 1-hexene.

Predict the product of the following reactions.

(b)

What reagents should be used to carry out the following syntheses?

Answer Problem 39, parts a–h, using 2-butyne as the starting material instead of propyne.

g. excess H₂, Pd/C

Predict the product of the following hydrogenation reactions.

(b)

What reaction would acetylene likely undergo if it were kept at 1500°C for too long?

Hydrogenation of which alkynes would produce the following cis-alkenes?

(b)