14. Synthetic Techniques

Beginning with the molecules on the left, provide a synthesis of the molecule on the right. The ideal number of steps is indicated over the reaction arrow, although there may be alternate routes worth considering.

(b)

Show how each of the following compounds can be prepared using the given starting material, any needed inorganic reagents, and any ­organic compound that has no more than four carbons:

a.

Beginning with the molecules on the left of each chemical equation, synthesize the molecules shown. While there can be multiple ways of doing each synthesis, the minimum number of steps necessary is indicated over each reaction arrow.

(b)

Show how you would accomplish the following synthetic conversions. You may use any additional reagents and solvents you need.

(d)

Show how the following compound can be prepared from the given starting material. Draw the structure of the compound that is formed in each step of the synthesis.

Show how each of the following compounds can be synthesized from the given starting materials:

c.

Show how you would synthesize each compound, beginning with acetylene and any necessary additional reagents

(b)

When doing synthesis, you will often find yourself repeating the same series of steps. To see this in action, synthesize the following aldehydes beginning with an organic molecule containing three carbons or fewer.

(d)

For each of the following target molecules, design a multistep synthesis to show how it can be prepared from the given starting material:

c.

Reaction of the acetylide with the epoxide shown will not form the desired product. What side reaction occurs instead? Why?

Synthesize the following molecules beginning with only organic molecules containing three carbons or fewer.

(e)

Complete the following synthesis by providing the necessary reagents.

Predict the products formed when CH₃CH₂–C≡C:^–Na⁺ reacts with the following compounds.

(d) cyclohexanone

(e) CH₃CH₂CH₂CHO

Show how you would synthesize the following compounds, starting with acetylene and any compounds containing no more than four carbon atoms.

g. pentanal, CH₃CH₂CH₂CH₂CHO

h. pentan-2-one, CH₃–CO–CH₂CH₂CH₃

i. (±) 3,4-dibromohexane