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Robert Burns Woodward
(1917 - 1979)
American chemist best known for his syntheses of complex organic substances,
including quinine (1944), cholesterol and cortisone (1951), and vitamin
B12 (1971). He was awarded the Nobel Prize for Chemistry in 1965.
Education and early career.
Woodward was attracted to chemistry at an early age and entered the
Massachusetts Institute of Technology in 1933. Involvement with chemistry
at the expense of other subjects caused his suspension for a semester
but also resulted in his collaboration on three research papers. Awarded
the B.S. degree in 1936 and the Ph.D. degree a year later, he immediately
became associated with Harvard, becoming professor (1950-60) and Donner
professor of science (1960-79). He was uniquely honoured by the founding
of the Woodward Research Institute in Basel, Switz., by the Ciba pharmaceutical
company in 1963. He then directed research activities both in Cambridge
and in Basel. Woodward was married in 1938 to Irja Pullman and in 1946
to Eudoxia Muller; he had three daughters and a son.
The chemistry of natural products served as the base for Woodward's
broad engagement in organic chemistry. The first result of this involvement
was a series of four papers (1940-42), based on work in the steroid
field, delineating rules for the correlation of ultraviolet spectra
with molecular structure. His early recognition that physical measurement
had greater power than chemical reaction to reveal structural features
led to his development of those rules (Woodward's rules). During World
War II, the extensive research in England and the United States to unravel
the structure of penicillin foundered on incorrect deductions from misleading
chemical behaviour until it was ultimately clarified by spectroscopic
measurements. Woodward correlated the work of this project into a final
deduction of structure (1945) and, during the next two decades, championed
the development of several spectroscopic techniques, which have reduced
the problem of structure determination to a relatively commonplace procedure.
Woodward's achievements in the field of structure determination were
more than mere solutions of particular problems: they were demonstrations
of new approaches and reasoning that have guided others and increased
the power of the discipline. The structures of complex natural products
deduced by Woodward include those of penicillin (1945), patulin (1948),
strychnine (1947), oxytetracycline (1952), cevine (1954), carbomycin
(1956), gliotoxin (1958), ellipticine (1959), calycanthine (1960), oleandomycin
(1960), streptonigrin (1963), and tetrodotoxin (1964). His delineation
of the structure of magnamycin revealed a previously unknown family
of natural products, the macrolide antibiotics, for which he also proposed
a mode of formation in nature. He also first proposed the correct biosynthetic
pathway to the steroidal hormones in living organisms.
Woodward, widely considered the father of modern organic synthesis,
was, without doubt, the most accomplished synthesist of complex molecules.
Beginning with his synthesis of quinine in 1944, he demonstrated that
the understanding of chemical reaction mechanisms made possible the
planning and successful execution of extended sequences of reactions
to build up complex compounds in the laboratory. The conception and
planning of these elaborate programs, requiring a balanced utilization
of all the tools and knowledge of the subject, is considered by many
the most demanding form of organic chemical research. The requisite
intellectual discipline, largely initiated by Woodward, did indeed become
a major endeavour in organic chemistry.
Synthesis of steroids.
Following the synthesis of quinine, he undertook and completed the first
total synthesis of the steroids cholesterol and cortisone (1951) and
then the related terpene lanosterol (1954). In 1954 syntheses of strychnine
and lysergic acid were announced, followed in 1956 by a synthesis of
reserpine that has become a model of elegant technique and has been
used commercially for reserpine production. Subsequent achievements
included the synthesis of chlorophyll (1960), tetracycline (1962), colchicine
(1963), and cephalosporin C (1965). In collaboration with Albert Eschenmoser
of the Federal Institute of Technology in Zurich (and, over a decade,
about 100 coworkers in the two laboratories), Woodward completed in
1971 the synthesis of the complicated coenzyme vitamin B12 (cyanocobalamin)
by a sequence of more than 100 reactions. This monumental work involved
a scale of concerted activity quite unprecedented in any previous synthetic
effort in chemistry. The work on vitamin B12 led to the recognition
and formulation, with Roald Hoffmann, of the concept of conservation
of orbital symmetry, explicating a broad group of fundamental reactions--probably
the most important theoretical advance of the 1960s in organic chemistry.
At the time of his death Woodward was working on the synthesis of erythromycin.
Woodward's work was central to the chemical thought of the times, and
his influence on other organic chemists was greater than that of any
other. He was awarded numerous honorary degrees and held many honorary
lectureships. His other honours included the Davy Medal of the Royal
Society (England, 1959), the Pius XI Gold Medal (Pontifical Academy
of Science, Vatican, 1961), the National Medal of Science (United States,
1964), the Order of the Rising Sun (Japan, 1970), the Nobel Prize for
Chemistry (1965), and other medals and awards. Woodward was a member
of the National Academy of Sciences, Washington, D.C.; the Royal Society,
London; and honorary member, or fellow, of several other scientific
societies in various countries.
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