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.
The target molecule is 2-pentanol. Alcohols can be prepared by reduction of carbonyls, or by reaction of a carbonyl compound with a Grignard reagent. The product shown can be prepared from acetaldehyde (ethanal) by addition of the Grignard reagent prepared from 1-bromopropane; therefore, the desired product can be prepared by conversion of butanoic acid to 1-bromopropane using the Hunsdiecker reaction, conversion of this to a Grignard reagent and reaction with acetaldehyde.
The target molecule is an alkene and two carbons have been added to the carbon chain. Alkenes can be prepared by elimination reactions, or by reaction of a carbonyl compound with a Wittig reagent. The product shown can be prepared from acetaldehyde (ethanal) by addition of the Wittig reagent prepared from 1-bromobutane; therefore, the desired product can be prepared by reduction of butanoic acid to the alcohol, conversion of the alcohol to 1-bromobutane using PBr3, conversion of this to a Wittig reagent and reaction with acetaldehyde.
The target molecule is a ketone and two carbons have been added to the carbon chain. Ketones can be prepared by oxidation of the corresponding secondary alcohol. The required alcohol can be prepared from acetaldehyde (ethanal) by addition of the Grignard reagent prepared from 1-bromobutane; therefore, the desired product can be prepared by reduction of butanoic acid to the alcohol, conversion of the alcohol to 1-bromobutane using PBr3, conversion of this to a Grignard reagent, reaction with acetaldehyde to give the alcohol, and finally, oxidation to give the ketone.
The target molecule is 2-pentanol. Alcohols can be prepared by reduction of carbonyls, or by reaction or a carbonyl compound with a Grignard reagent. The product shown can be prepared from acetaldehyde (ethanal) by addition of the Grignard reagent prepared from 1-bromopropane; therefore, the desired product can be prepared by conversion of butanoic acid to 1-bromopropane using the Hunsdiecker reaction, conversion of this to a Grignard reagent and raction with acetaldehyde.
The target molecule is an alkene and two carbons have been added to the carbon chain. Alkenes can be prepared by elimination reactions, or by reaction of a carbonyl compound with a Wittig reagent. The product shown can be prepared from acetaldehyde (ethanal) by addition of the Wittig reagent prepared from 1-bromobutane; therefore, the desired product can be prepared by reduction of butanoic acid to the alcohol, conversion of the alcohol to 1-bromobutane using PBr3, conversion of this to a Wittig reagent and reaction with acetaldehyde.
The target molecule is a ketone and two carbons have been added to the carbon chain. Ketones can be prepared by oxidation of the corresponding secondary alcohol. The required alcohol can be prepared from acetaldehyde (ethanal) by addition of the Grignard reagent prepared from 1-bromobutane; therefore, the desired product can be prepared by reduction of butanoic acid to the alcohol, conversion of the alcohol to 1-bromobutane using PBr3, conversion of this to a Grignard reagent, reaction with acetaldehyde to give the alcohol, and finally, oxidation to give the ketone.