Carboxylic Acids - Synthesis
For each of the conversions shown on the left, provide the reactants and reagents necessary to convert either of the starting materials shown below into the final product. Pay particular attention to the regiochemistry and stereochemistry of the reactions you utilize.Click the mouse on the final product to view the answer;
click on the arrow for help with the synthesis.
In order to prepare 1-butanol from butanoic acid, you must simply reduce the carbonyl group to the alkane. This can be done readily using either BH3/THF/H3O+ or LiAlH4.
The target molecule is 1-bromobutane. Alkyl bromides can be prepared from the corresponding alcohols by reaction with PBr3. The required alcohol has the same carbon skeleton as the starting material, butanoic acid; therefore, the desired product can be prepared by simple reduction of the acid to the alcohol using either BH3/THF/H3O+ or LiAlH4, followed by bromination with PBr3.
The target molecule is pentanoic acid. The final product has one additional carbon in the parent chain and is a carboxylic acid. We can add one carbon and synthesize carboxylic acids by the reaction of a Grignard reagent with carbon dioxide. The required Grignard reagent has the same carbon skeleton as the starting material, butanoic acid; therefore, the desired product can be prepared by simple reduction of the acid to the alcohol using either BH3/THF/H3O+ or LiAlH4, followed by bromination with PBr3, conversion to a Grignard reagent and carboxylation.
In order to prepare 1-butanol from butanoic acid, you must simply reduce the carbonyl group to the alkane. This can be done readily using either BH3/THF/H3O+ or LiAlH4.
The target molecule is 1-bromobutane. Alkyl bromides can be prepared from the corresponding alcohols by reaction with PBr3. The required alcohol has the same carbon skeleton as the starting material, butanoic acid; therefore, the desired product can be prepared by simple reduction of the acid to the alcohol using either BH3/THF/H3O+ or LiAlH4, followed by bromination with PBr3.
The target molecule is pentanoic acid. The final product has one additional carbon in the parent chain and is a carboxylic acid. We can add one carbon and synthesize carboxylic acids by the reaction of a Grignard reagent with carbon dioxide. The required Grignard reagent has the same carbon skeleton as the starting material, butanoic acid; therefore, the desired product can be prepared by simple reduction of the acid to the alcohol using either BH3/THF/H3O+ or LiAlH4, followed by bromination with PBr3, conversion to a Grignard reagent and carboxylation.