Design synthesis

This is the domain of synthesis design, and the planning of chemical reactions. 

After approaches to the solution of the major tasks in chemoinformatics have thus been outlined, these methods are put to work in specific applications. Some of these apphcations, such as structure elucidation on the basis of spectral information, reaction prediction, computer-assisted synthesis design or drug design, are presented in Chapter 10. 

In 1967, work was presented from a Sheffield group on indexing chemical reactions for database budding. In 1969, a Harvard group presented its first steps in the development of a system for computer-assisted synthesis design. Soon afterwards, groups at Brandeis University and TU Munich, Germany, presented their work in this area. 

Atomic and bond hash codes are helpful in structure manipulation programs, e.g., in reaction prediction or in synthesis design [99]. 

Clearly, for symmetry reasons, the reverse process should also be considered. In fact, early versions of our reaction prediction and synthesis design system EROS [21] contained the reaction schemes of Figures 3-13, 3-15, and 3-16 and the reverse of the scheme shown in Figure 3-16. These four reaction schemes and their combined application include the majority of reactions observed in organic chemistry. Figure 3-17 shows a consecutive application of the reaction schemes of Figures 3-16 and 3-13 to model the oxidation of thioethers to sulfoxides. 

To be able to define reaction planning, reaction prediction, and synthesis design To know how to acquire knowledge from reaction databases To understand reaction simulation systems... 

To recognize the different levels of representation of biochemical reactions To understand metabolic reaction networks To know the principles of retrosynthetic analysis To understand the disconnection approach To become familiar with synthesis design systems... 

This is the domain of synthesis design (Figure 10.3-Ic). The product of the reaction is known and one has to work back from the reaction product to synthesis precursors that provide, on reacting, the desired target compound. This procc.ss has to be repeated until one arrives at available starting materials, A , Synthesis design is the theme of Section 10.3-2. 

How do chemists find a pathway to the synthesis of a new organic compound They try to find suitable starting materials and powerful reactions for the synthesis of the target compound. Thus, synthesis design and chemical reactions are deeply linked, since a chemical reaction is the instrument by which chemists synthesize their compounds synthesis design is a chemist s major strategy to find the most suitable procedure for a synthesis problem. 

Because of the complexity of the problem and the large amount of program development work that has to go into a synthesis design system, only a few groups worldwide have been active in this area. Here, we mention only a selection of the major ideas and achievements in this area. It is not the intention to give a comprehensive overview. For this, interested readers can consult Chapter X, Section 3.2 in the Handbook. This chapter presents one such system, the WODCA program, in greater detail. 

Reaction databases contain a wealth of reactions performed in the laboratory and published in the literature, i.c., in contrast to the transform libraries of synthesis design programs they contain raw, uninterpreted reaction information. In Figure 10,3-41 a schematic representation of a reaction in a reaction database is given. 

Tutorial Synthesis Design with the WODCA Program... 

Reaction prediction treats chemical reactions in their forward direction, and synthesis design in their backward, retrosynthetic direction,... 

Reaction databases present a rich source of information for the extraction of knowledge for reaction prediction and synthesis design,... 

Several concepts for the implementation of synthesis design system have appeared since the early 1970s. 

R. Barone, M. Chanon, Synthesis design, in The Encyclopedia of Computational Chemistry, Vol. 4,... 

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