14. Synthetic Techniques

Show how you would convert the following starting materials into the target compound. You may use any additional reagents you need.

Develop syntheses for the following compounds, using acetylene and compounds containing no more than four carbon atoms as your organic starting materials.

(b) cis-1-ethyl-2-methylcyclopropane

Given the target molecule ${\mathrm{Ph}}_2\mathrm{CO}$ (benzophenone), which of the following disconnections leads to the most reasonable retrosynthesis?

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

(g)

Supply the reagents necessary to accomplish the following transformation.

Give the structures of the products represented by letters in this synthesis.

Part 2:

A, a compound with molecular formula C₆H₁₀, contains three methylene units. A reacts with one equivalent of H₂ over Pd/C to yield B. A reacts with aqueous acid to form a single product, C, and undergoes hydroboration/oxidation to form a pair of enantiomers, D and E. Ozonolysis of A followed by reaction with dimethyl sulfide forms F with molecular formula C₆H₁₀O₂. Provide structures for A–F.

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

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

a.

Propose a synthesis

Starting from bromobenzene and any other reagents and solvents you need, show how you would synthesize the following compounds. Any of these products may be used as starting materials in subsequent parts of this problem.

d. 3-phenylprop-2-en-1-ol

Work backward to show how the cyclopropane would be synthesized from the chloroalkane shown.

Propose a synthesis of the carbonyl(s) using the (ii) dihydroxylation/periodic acid cleavage pathways.

(b)

Using the given starting material, any necessary inorganic reagents, and any carbon-containing compounds with no more than two carbons, indicate how the following syntheses could be carried out:

a.

Show how you would accomplish the following synthetic conversions.

(c) 2−methylcyclohexanol → 1−bromo−1−methylcyclohexane