Leopold Ruzicka

Location: Fifth Floor, West Wing, South Wall, Sequence 1

Source: Professor P. E. Fanta and the Wilkens-Anderson Company

Sponsor: Cynthia and Robert E. Maleczka, Jr.

"For his work on polymethylenes and higher terpenes" Ruzicka received the 1939 Nobel Prize in Chemistry (shared with Adolf Butenandt, who received it for isolation of the sex hormones estrone, androsterone and progesterone). Ruzicka was interested in the large ring ketones civetone and muscone because of their musk odor, and showed through degradation and synthesis that they had 17- and 15-membered carbon rings. This was highly novel work at the time, because Adolph von Bayer, a giant of 19th century chemistry (see portrait) had predicted that such rings would be strained and too unstable to exist. In his work on terpenes, Ruzicka made extensive use of the isoprene rule, first formulated by Otto Wallach in 1887 (see portrait) but largely ignored until Ruzicka recognized its general significance. He defined monoterpenes as having carbon skeletons with two 5-carbon isoprene units, sesquiterpenes with three isoprenes, and so on. His "biogenetic isoprene rule", which stated that among all possible structures of a terpene, the favored one can be derived mechanistically by the cyclization of an aliphatic precursor such as geraniol, farnesol, geranyl geraniol and squalene, became the crowning glory of his life's work. He published close to 600 papers.

Ruzicka was born in Croatia (though he published under Leopold, his given name was Lavoslav) but, after studies in Germany he moved to Switzerland where he spent most of his career at the Swiss Federal Institute of Technology (ETH). He was an unconventional lecturer, scribbling blackboards full of reactions and formulas at a furious pace at 8:00 AM; he believed that by copying these, they would enter the subconscious of the student. He was both admired and feared by them.