21. Aldehydes and Ketones: Nucleophilic Addition

Show how you would accomplish the following syntheses efficiently and in good yield. You may use any necessary reagents.

(b)

Show how Wittig reactions might be used to synthesize the following compounds. In each case, start with an alkyl halide and a ketone or an aldehyde.

(a) Ph–CH=C(CH₃)₂

(b) Ph–C(CH₃)=CH₂

Show how Wittig reactions might be used to synthesize the following compounds. In each case, start with an alkyl halide and a ketone or an aldehyde.

(c) Ph–CH=CH–CH=CH–Ph

(d)

Predict the major products of the following reactions.

(h)

(a) Outline the syntheses indicated in Solved Problem 18-2, beginning with aldehydes and alkyl halides.

(b) Both of these syntheses of 1-phenylbuta-1,3-diene form the central double bond. Show how you would synthesize this target molecule by forming the terminal double bond.

Using cyclohexanone as the starting material, describe how each of the following compounds can be synthesized:

f.

Show how you would synthesize octanal from each compound. You may use any necessary reagents.

(f) octanoic acid

Show how you would synthesize octanal from each compound. You may use any necessary reagents.

(g) ethyl octanoate

Show how you would accomplish the following syntheses.

(b) benzonitrile → propiophenone

Show how you would synthesize each compound from starting materials containing no more than six carbon atoms.

Show how you would accomplish the following synthetic conversions efficiently and in good yield. You may use any necessary additional reagents and solvents.

(e)

Show how you would accomplish the following syntheses efficiently and in good yield. You may use any necessary reagents.

(a) acetaldehyde → lactic acid, CH₃CH(OH)COOH

Show how you would synthesize octan-2-one from each compound. You may use any necessary reagents.

(a) heptanal

Show how you would synthesize octan-2-one from each compound. You may use any necessary reagents.

(b) oct-1-yne

Show how you would synthesize octan-2-one from each compound. You may use any necessary reagents.

(c) 2,3-dimethylnon-2-ene