14. Synthetic Techniques

Determine the structures of compounds A through G, including stereochemistry where appropriate.

Supply the reagents necessary to accomplish the following transformation.

Propose a synthesis

Supply the reagents necessary to accomplish the following transformation.

Compound A (C₇H₁₁Br) is treated with magnesium in ether to give B (C₇H₁₁MgBr), which reacts violently with D₂O to give 1-methylcyclohexene with a deuterium atom on the methyl group (C). Reaction of B with acetone (CH₃COCH₃) followed by hydrolysis gives D (C₁₀H₁₈O). Heating D with concentrated H₂SO₄ gives E (C₁₀H₁₆), which decolorizes two equivalents of Br₂ to give F (C₁₀H₁₆Br₄). E undergoes hydrogenation with excess H₂ and a Pt catalyst to give isobutylcyclohexane. Determine the structures of compounds A through F, and show your reasoning throughout.

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

Using any necessary inorganic reagents, show how you would convert acetylene and isobutyl bromide to

(b) (±)-2,7-dimethyloctane-4,5-diol.

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.

(a)

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

(g)

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.

(a)

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 synthesize the following compounds. As starting materials, you may use any alcohols containing four or fewer carbon atoms, cyclohexanol, and any necessary solvents and inorganic reagents.

(h)

Show how you would synthesize the following compound. As starting materials, you may use any alcohols containing five or fewer carbon atoms and any necessary solvents and inorganic reagents.

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.

(b)

Suggest a synthetic scheme, involving a protecting group, to generate the molecule shown starting with the molecule at the left.

(a)