Otto Diels was a German organic chemist who discovered a technique of atomic combination which led to the synthesis of an important group of organic compounds.
Background
Otto Diels was born on January 23, 1876, in Hamburg, Germany. His father, Hermann, was a professor of classical philology at the University of Berlin; his brother Paul, professor of Slavic philology at Breslau; and his brother Ludwig, professor of botany at Berlin. His mother, the former Bertha Dubell, was the daughter of a district judge.
Education
Diels studied in Berlin at Joachimsthalsches Gymnasium. As a student, Diels, with his brother Ludwig, eagerly conducted chemical experiments. He studied chemistry in Berlin from 1895 to 1899 and in 1899 obtained the Ph.D., magna cum laude, with a dissertation entitled “Zur Kenntnis der Cyanverbindungen.” From 1899 he studied under Emil Fischer.
Career
Diels served as an assistant of Emil Fischer until he became a lecturer in 1904. He became department head in 1913 and in 1914 was appointed associate professor at the Chemical Institute of the Royal Friedrich Wilhelm (now Humboldt) University. In 1916 Diels accepted an invitation from Christian Albrecht University, Kiel, where he served as full professor and director of the Chemical Institute until his final retirement in October 1948.
Diels recorded his personal memories in a manuscript entitled “Werden und Wirken eines Chemieprofessors,” as well as in an illustrated diary (Diels was a weekend painter) which has been reviewed in detail by Sigurd Olsen.
Toward the end of World War II air raids completely destroyed the Chemical Institute, the library, and his home. Since there was no possibility of carrying on his work and he was suffering from the general privations, Diels filed for retirement in September 1944, to be effective in March 1945. Nevertheless, in 1946 he agreed to resume the directorship of the Chemical Institute, and at the age of seventy he started anew, under the most primitive conditions in makeshift quarters.
Diels’ work, which was in the field of pure organic chemistry with no significant digressions into bio-chemistry or into physical chemistry, reveals an outstanding experimenter with original and bold ideas. His Einführung in die organische Chemie (1907), which went through nineteen editions by 1962, has a clarity and a precision that have made it one of the most popular textbooks in the field.
In 1906 Diels obtained carbon suboxide by dehydrating malonic acid and investigated its properties. In the same year, with E. Abderhalden, he began his research on cholesterol, the structure of which had not yet been determined. He isolated pure cholesterol from gallstones and converted it into “Diels’ acid” through cleavage by oxidation. Meanwhile, Windaus had proposed a formula for cholesterol that did not agree with more recent observations. As a result, Diels decided first to establish the aromatic basic structure of cholesterol. Dehydration of cholesterol with sulfur was unsuccessful.
With Kurt Alder, Diels developed over a period of twenty-two years the diene synthesis, which came to occupy a key position in the theory and practice of organic chemistry.
Diels published thirty-three papers on the practical applications of this new method of synthesis. Windaus, in the field of steroids, used it for the separation of ergosterol and its irradiation products. In a series of important terpenes, such as camphor, dl-santene, butadiene, and a-phellandrene, the structure could be confirmed by synthesis, since these substances are composed of isoprene residues, the building blocks of the diene structure. Also, great progress could be made in the synthesis of heterocyclics.
In his Nobel address, “Darstellung und Bedeutung des aromatischen Grundskeletts der Steroide,” Diels compared his research on cholesterol with his work in diene synthesis.
Diels was a member of the academies of sciences of Göttingen and Halle (Leopoldina) as well as the Bavarian Academy of Sciences.
Personality
Diels was considered somewhat reserved, yet possessed of a good sense of humor. He was an honest, sensitive, an outstanding educator, and a devoted family man.
Diels was fond of music and reading and liked traveling. He was also fond of mountaineering in his younger days.
Interests
music, reading, traveling, mountaineering
Connections
Diels married Paula Geyer in 1909, and had three sons and two daughters, of which, two sons were killed in action on the eastern front during World War II.