Nobel Prize Recipient. Otto Diels, a German organic chemist, received international recognition after being awarded the 1950 Nobel Prize in Chemistry. He shared jointly his award with Dr. Kurt Alder. Between 1932 and 1950, he received 32 nominations for the Nobel candidacy. According to the Nobel Prize Committee, the two men received the award "for their discovery and development of the diene synthesis." In 1928 he and his student Alder discovered a reaction, in which one dien was changed into a ring-shaped molecule with six carbon atoms. This discovery became very important for industrial use, especially in making rubber and later pharmaceuticals. The diene synthesis is considered the Diels-Alder Reaction. The two men published a paper on their scientific find, "Syntheses of the Hydroaromatic Series." Born Otto Paul Hermann Diels, the son of a professor of classical philology at the University of Berlin, his family relocated to Berlin when he was two years old. He had two brothers, Paul, who became a professor of Slavic philology at Breslau, and Ludwig, who became a professor of botany at Berlin. In 1895 he entered Berlin University, studying chemistry, together with other science subjects, under Dr. Emil Fischer, 1902 Nobel Prize in Chemistry recipient. After graduating in 1899 magna cum laude with his Ph.D., he was appointed assistant at the Institute of Chemistry at Berlin University and succeeded as a lecturer in 1904, a professor in 1906, and Head of Department in 1913. In 1914 he was appointed associate professor at the Chemical Institute of the Royal Friedrich Wilhelm. He became Professor at the University of Berlin in 1915 yet, the following year, transferred to the University of Kiel as Professor and Director of the Institute of Chemistry, remaining at that facility until his retirement in March of 1945. He started at the University of Kiel during World War I, meeting all the difficulties of being in the war and then losing the war, yet build the university science department to be outstanding. He was at the University of Kiel when he and Alder did their research, which earned them the Nobel Prize. His first discovery was in the field of inorganic chemistry, where he was the discoverer of an oxide of carbon having some unusual properties, which was called carbon suboxide. At that point, he began his organic chemistry career. His research led to the development of alkaloids and insecticides at a low cost without using any catalyst. He isolated pure cholesterol from gallstones and converted it into "Diels's acid" through cleavage by oxidation. In 1907 he published the German textbook "Introduction to Organic Chemistry," which has gone through 15 editions and is still very popular in the 21st century. He published numerous scientific articles in professional journals. Besides the Nobel Prize, he received the Gold Medal at the St. Louis International Exhibition in the United States in 1904, the Adolf von Baeyer Medallion in 1930, and The Order of Merit of the Federal Republic of Germany in 1952. With the isolation of Germany from the world for over a decade under the Nazi Party, his international awards may have been limited and his Nobel Prize presented earlier. He held the honorary degree of Doctor of Medicine from the University of Kiel and was a member of the Academies of Halle, Munich, and Göttingen. He married and the couple had three sons and two daughters. Two of his sons were killed in action serving in the German Army in World War II while on the eastern front with the Russians. The laboratory and library at the Institute of Chemistry, along with his home, were destroyed by the Allied bombings of Germany during the war. After the war, he and his family did not have the simple basis for daily living. Although he had retired in 1945, in 1946, he agreed to resume the directorship of the Chemical Institute, and at the age of seventy, he rallied to start again under the most primitive conditions in makeshift quarters. He died of heart failure. He has a memorial plaque on the site of the old institute.