The undisputed master of chemistry is Nature, and the variety of substances it routinely creates has long been a source of inspiration and perspiration for chemists. Investigating and recreating the natural substances essential for life is a painstaking process; their size and complexity makes anything other than the simplest compounds almost impossible to reproduce under laboratory conditions. By taking a leaf out of Nature’s lab book, Sir Robert Robinson changed the way in which chemists thought about recreating natural products.
Robinson’s breakthrough involved the alkaloids, a set of well-known and complex plant chemicals, including cocaine, morphine and opium, which exert profound effects on living things. Robinson unravelled the structures of many of these alkaloids, including morphine and strychnine, and he also synthesized several of them from simple starting materials. His strong conviction that the way Nature builds up its complex chemicals differs from the way in which chemists create them in the laboratory was realized in his synthesis of the alkaloid tropinone. Foregoing the usual and arduous approach of forcing a long succession of small artificial chemical building blocks together to form a complete molecule, Robinson successfully showed how tropinone can be created by combining larger precursor chemicals that resembled three subfragments of the compound. He also showed that this molecular assembly method could be achieved using experimental conditions similar to that found in living systems, a far cry from the less-than-natural conditions of high temperatures and pressures normally used by chemists to force chemicals together.
Other notable milestones in Robinson’s illustrious career in organic chemistry include completely synthesizing the complex red and blue pigments in flowers and fruits from simpler chemicals, and relating their structure to their colour. Robinson pioneered work on synthesizing secondary sex hormones, and creating synthetic versions of penicillin and malaria drugs. He also answered fundamental questions concerning the way in which negatively charged electrons alter their arrangement around atoms during the course of organic reactions. But it was mainly in recognition of revealing Nature’s way of creating the alkaloids that Robinson was awarded the 1947 Nobel Prize in Chemistry.