He taught chemists to work backwards

The 1990 Nobel Prize in Chemistry was not shared. It went to one man, a grandson of emigrants from Lebanon, raised in Methuen, Massachusetts, and the idea that won it was to plan a molecule from the finished end.

On 7 October 2026 the Royal Swedish Academy of Sciences gave the Nobel Prize in Chemistry to Henri B. Kagan and Kenso Soai, for discoveries that let chemists push a reaction towards one mirror image of a molecule rather than an even mix of both. In medicine that matters, the academy explained, because usually only one of the two mirror images does the job.

Thirty six years earlier, almost to the week, the same academy wrote about the same kind of problem. Its press release of 17 October 1990 described catalysts that give only one mirror isomer of the product, and it credited them to a professor at Harvard. His name was Elias James Corey. The Nobel record gives him a prize share of one in one. He did not share it with anybody.

The record lists him as born in Methuen, Massachusetts, USA. It does not mention Lebanon. His own autobiography, written for the Nobel Foundation, does, in its first paragraph.

He was born in July 1928. Eighteen months later his father, Elias, a businessman in Methuen, about thirty miles north of Boston, died. His mother, Fatina, born Hasham, then changed the boy’s name from William to Elias. He wrote that he did not remember his father, and that he had always wanted to be a worthy son to him and to the mother who raised four children through the Depression and the Second World War.

His grandparents on both sides, he wrote, had emigrated from Lebanon to the United States, and they knew how to cope with adversity.

In 1931 his mother’s sister, Naciby, and her husband, John Saba, who had no children of their own, joined the household. The whole family lived together in one large house in Methuen. He called his aunt and uncle second parents, and credited his aunt, the stricter of the two sisters, with teaching him to take pleasure in a job well done, however ordinary.

Two details differ between sources. Wikipedia spells his mother’s name Fatima; the Nobel autobiography, in his own words, says Fatina, and we follow him. Wikipedia also says the surname Corey was anglicised from Khoury. The autobiography does not say so, so that one is Wikipedia’s claim, not his.

He finished high school in Lawrence, the next town, at sixteen, and entered the Massachusetts Institute of Technology a few weeks later, in July 1945. He thought he might study electronic engineering. He became, in his word, a convert to chemistry before he had taken a single engineering course.

He graduated in three years and stayed at MIT for a doctorate under John C. Sheehan, in a programme on synthetic penicillins, finishing at the end of 1950. At twenty two he joined the University of Illinois at Urbana-Champaign as an instructor. In 1956, at twenty seven, he was made a full professor. In 1959 he accepted a professorship at Harvard, and he wrote that he regarded that offer as the most gratifying of his professional honours. He wrote that in 1990, the year of the Nobel.

The idea arrived in a bad month. In the autumn of 1957 he was on his first sabbatical, spending part of it at Harvard at the invitation of Robert B. Woodward. In September his uncle John died. Corey had seen him two days earlier.

He went back to work alone, and in early October, he wrote, several of the key ideas for a logical and general way of thinking about chemical synthesis came to him. He sketched a plan for one molecule, longifolene, and showed it to Woodward, who responded with enthusiasm. Later that year, visiting Sune Bergström’s department in Lund, he became interested in the prostaglandins. His group went on to make the first chemical syntheses of prostaglandins in the mid 1960s.

Many earlier syntheses, the academy wrote, had been done more or less by intuition. Asking a chemist why he chose those starting materials, the press release said, could be as meaningless as asking Picasso why he painted as he did. It compared the planning of a synthesis to three dimensional chess with forty pieces a side, and noted that more than 35,000 usable methods of synthesis were already described in the literature.

Corey’s answer, which he named retrosynthetic analysis in the 1960s, was to start from the end. Take the molecule you want. Decide which bonds to break. Break it into simpler pieces, then break those again, until every piece is something already known or something you can buy. Then build forwards.

Two things followed from making it a method rather than a gift. First, it could be taught. Corey wrote that, using these ideas, first year graduate students could learn to design sophisticated syntheses in three months. Second, it could be programmed. The academy noted that he showed the logic was amenable to computers, and Wikipedia records that his group built a program called LHASA to search for routes to a target molecule.

The 1990 press release says Corey had synthesised about a hundred important natural products. It names gibberellic acid, a plant hormone, in 1978, and a ginkgolide, the active substance in a ginkgo tree extract used as a folk medicine in China. It says his most important syntheses were of the eicosanoids, among them prostaglandins and leukotrienes, compounds the body makes in tiny amounts, and that many important pharmaceuticals were commercially available thanks to his contributions.

To get there, the academy wrote, he had to develop some fifty new or much improved reactions and reagents, and it said it was probable that no other chemist had developed such a comprehensive and varied set of methods. That is the committee’s judgement, in its own press release, and we give it as theirs.

The counts moved after 1990, and the sources do not agree. Wikipedia, citing the group’s own records, says at least 265 natural compounds and at least 302 methods came out of the Corey group since 1950. Harvard’s department page says he is the author of more than 1,000 scientific publications; Wikipedia says more than 1,100. Harvard says he has received about 70 awards and honorary degrees; Wikipedia says more than 40 major awards. Harvard lists among them the National Medal of Science, the Japan Prize and the Priestley Medal of the American Chemical Society, and calls him one of the most cited authors in science.

In 1990 Corey wrote that his research family included about one hundred and fifty university professors and an even larger number of scientists in the pharmaceutical and chemical industries. Wikipedia puts the number of people who had been members of the group at about seven hundred by 2010.

One of them came from Nagoya in 1969. Ryoji Noyori wrote in his own Nobel autobiography that Corey had agreed to take him as a postdoctoral fellow, and that the Harvard stay, together with earlier work in Japan, led to his life long research on asymmetric hydrogenation. In 2001 Noyori shared the Nobel Prize in Chemistry for work on chirally catalysed hydrogenation reactions. Mirror images again.

Harvard still lists him as Sheldon Emory Professor Emeritus. The earlier Lubnan pieces keep finding the record of the diaspora written by other people: a clerk, a census, a consulate. This one is different. The record was written by the man himself, for the Nobel Foundation, and he put his Lebanese grandparents in the opening paragraph.

What he left is not only a prize. It is a way of thinking that a first year student could learn in three months, and a lab that sent its people into universities and drug companies around the world. That is what excellence looks like when it compounds.

So it goes on the record. With the dates, the disagreements and the name his mother gave him.