Carry out a chain of transformations: methyl ester of ethanic acid ⇒ acetic acid ⇒ ethanal ⇒ ethanol ⇒ ethene.

1. CH3-COO-CH3 + H2O = CH3-COOH + CH3-OH, hydrolysis to the starting alcohol and acid, water.
2. The general method for obtaining aldehydes from the corresponding acids consists of two reactions:
With the action of phosphorus pentachloride PCl5 on an acid, an acid chloride can be obtained:
CH3-COOH + PCl5 = CH3-COOCl + CH3OCl3 + HCl.
According to the Rosenmund reaction, the acid passes into the corresponding aldehyde:
CH3-COOCl + H2 = CH3-CHO + HCl.
3. CH3-CHO + Fe + HCl = C2H5OH + FeCl2.
4. 2C2H5OH = C2H4 + H2O, the reaction takes place when heated, in the presence of sulfuric acid.