Solutions for chemistry: synthesis of experiment and calculation

Making molecules is fundamental to the development of all new substances, i ncluding new materials and health products. Organic synthesis is engineerin g on an atomic scale, and requires techniques of mass production so that it is possible to make copies of molecules not just in hundreds or thousands, but in billions of billions of billions. As a result, organic synthesis is an extremely demanding discipline, requiring both a wide knowledge of chem istry and also the ability to develop complete strategies for the construct ion of molecules. If the last step of a synthesis does not work, then it ma y be necessary to begin again by altering the first step. Organic synthesis is sometimes compared with a game of chess, where the effects of the openi ng moves are felt right through to the end game, and where the number of po ssible situations is greater than can be comprehensively analysed by any co mputer. Chess, however, is succumbing to computers. Only the very best human chess players can compete on a level with the best chess-playing computers, and e very year the computers become more powerful. It is unlikely that the chess champion of the would will be human for ally of the third millennium. The best designers of organic syntheses are unquestionably human, at the end of the second millennium. For how much longer will this pre-eminence continue ? Quantum mechanics gives a good understanding of how molecules behave; but t he calculations required are much too time consuming for Schrodinger's equa tion to be able to compete with the best organic synthetists. Information t echnology enables computers to know the chemistry literature better than an y person! but this, in itself, is not sufficient to design syntheses of new compounds. The use of these two approaches together, however, may enable c omputers to design better syntheses. The development of the World Wide Web has shown that it is possible for computers to communicate on a global scal e! and this, coupled with developments in theoretical chemistry, may lead t o computers making useful contributions to synthetic strategies in the near future. This article gives a brief history of organic synthesis, highlighting the i ssues that make this such a demanding subject. It also sketches the develop ment of quantum theory, as applied to chemistry, and information technology tools. These techniques are just reaching the stage at which they may be a ble to interact constructively, and so solutions for chemistry may be avail able early in the new millennium.