Show how to synthesize each of the compounds shown below using alanine as your starting material. Give the structure of each product in your answer.
(i) alanine ethyl ester
(ii) (cyclohexanecarbonyl) alanine

Write the synthesis of ethyl propionate starting with a carboxylic acid as one of the reagents.

In a laboratory, a researcher added dicyclohexylacetic acid to an acidic solution of cyclohexanol but failed to acquire an ester. Identify the reason that prevented esterification of dicylohexylacetic acid.

Acetic acid is reacted with ethanol-¹⁸O in acidic conditions. Identify the labeled product(s) formed.

Draw a suitable mechanism for the esterification of 3-methylbutanoic acid with methanol.