Otto Paul Hermann Diels
German chemist. In 1950 he and his former assistant, Kurt Alder, were
jointly awarded the Nobel Prize for Chemistry for their research into
the synthesis of organic chemical compounds.
In 1927 Diels dehydrogenated cholesterol to produce 'Diels hydrocarbon'
(C18H16), an aromatic hydrocarbon closely related to the skeletal structure
of all steroids, of which cholesterol is one. In 1935 he synthesized
it. This work proved to be a turning point in the understanding of the
chemistry of cholesterol and other steroids.
Diels was born in Hamburg and studied at Berlin. He was director of
the Chemical Institute at the Christian Albrecht University in Kiel
Working with his assistant Alder, Diels developed the diene synthesis,
which first achieved success in 1928, when they combined cyclopentadiene
with maleic anhydride (cis-butenedioic anhydride) to form a complex
derivative of phthalic anhydride. Generally, conjugated dienes (compounds
with two double bonds separated by a single bond) react with dienophiles
(compounds with one double bond activated by a neighbouring substituent
such as a carbonyl or carboxyl group) to form a six-membered ring.
Besides the DA reaction, Diels is also known for having discovered carbon
suboxide (C3O2) and for his early research on the structure of cholesterol,
especially for the use of selenium (rather than sulfur) for dehydrogenations,
and for Diels' hydrocarbon (3'-methyl-1,2-cyclopentenophenanthrene)
which he obtained from cholesterol by that technique.
a textbook, Einfuhrung in die organische Chemie/Introduction to Organic