13. Alcohols and Carbonyl Compounds

Show how you would accomplish the following syntheses. You may use whatever additional reagents you need.

(c)

Predict the major products of the following reactions.

(d)

Two of the methods for converting alkyl halides to carboxylic acids are covered in Sections 20-8B and 20-8C. One is formation of a Grignard reagent followed by addition of carbon dioxide and then dilute acid. The other is substitution by cyanide ion, followed by hydrolysis of the resulting nitrile. For each of the following conversions, decide whether either or both of these methods would work, and explain why. Show the reactions you would use.

(a)

(b)

Predict the products of the following reactions.

(a) sec-butylmagnesium iodide + D₂O

(b) n-butyllithium + CH₃CH₂OH

(c) isobutylmagnesium bromide + but-1-yne

Point out the flaws in the following incorrect Grignard syntheses.

(a)

Show how you would accomplish the following synthetic conversions.

(c)

Show how you would accomplish the following synthetic conversions.

(d)

Compound A is an optically active alcohol. Treatment with chromic acid converts A into a ketone, B. In a separate reaction, A is treated with PBr₃, converting A into compound C. Compound C is purified, and then it is allowed to react with magnesium in ether to give a Grignard reagent, D. Compound B is added to the resulting solution of the Grignard reagent. After hydrolysis of the initial product (E), this solution is found to contain 3,4-dimethylhexan-3-ol. Propose structures for compounds A, B, C, D, and E.

Give the structures of the intermediates and products V through Z.

To practice working through the early parts of a multistep synthesis, devise syntheses of

(a) pentan-3-one from alcohols containing no more than three carbon atoms.

To practice working through the early parts of a multistep synthesis, devise syntheses of

(b) 3-ethylpentan-2-one from compounds containing no more than three carbon atoms.

Develop syntheses for the following compounds. As starting materials, you may use cyclopentanol, alcohols containing no more than four carbon atoms, and any common reagents and solvents.

(b) 1-chloro-1-ethylcyclopentane

Show how you would synthesize the following compounds from any starting materials containing no more than six carbon atoms.

(a)

Show how this 1° alcohol can be made from the following:

(b) formaldehyde

For each synthesis, start with bromocyclohexane and predict the products. Assume that an excess of each reactant is added so that all possible reactions that can happen will happen.

(a)