Thanks to the method they developed, it was possible to synthesize many organic compounds, starting from vitamin D and cortisone to synthetic rubber.
German organic chemist. Together with Otto Diels, he carried out the synthesis known as the "Diels-Alder reaction". He was born on July 10, 1902, in Königshütte, Germany (today Chorzosv in Poland). He studied chemistry at the University of Berlin. He became Otto Diels' assistant at the University of Kiel, where he received his doctorate in 1926, and was promoted to professor at the same university in 1934. Two years later, he took over the head of the research department of a large chemistry institution, and in 1940 he was appointed professor of chemistry at the University of Cologne and head of the chemistry institute. During World War II, he researched the industrial applications of dienes synthesis. He died on 20 June 1958 in Cologne.
Alder began working on diene reactions with his teacher while assistant to Otto Diels at the University of Kiel. The first product of this collaborative work was a review of the reactions of dienes and quinones (1928). During their research, they determined that when a conjugate diene reacts with an unsaturated hydrocarbon, it gives a cyclic compound that does not resemble the molecular structure known to date. For example, when four-carbon butadiene from the conjugate dienes class reacts with two-carbon ethylene from the alkenes (olefins) class of unsaturated hydrocarbons, cyclohexene, a six-carbon ring compound, is obtained:
This addition reaction, which does not require any catalyst, special conditions such as high temperature or pressure, and complex techniques, is called the "Diels-Alder reaction". Today, this is the most applied method, especially to obtain cyclic compounds with six carbons. The synthesis method with dienes allowed the synthesis of many organic compounds, starting from vitamin D and cortisone to synthetic rubber. The 1950 Nobel Prize in chemistry was awarded to Diels and Alder for their discoveries, which led to great developments, especially in the organic synthesis chemistry and petrochemical industry.