Computer aided organic synthesis: Development and implementation of a complete synthetic strategy

The concept of Complete Synthetic Strategy (CSS) is defined. A CSS differs from most strategies found in the literature in that it provides synthesis guidelines for a complete synthesis from start to finish, that is from the target down to and including the starting materials. One CSS covers only a particular type of synthesis. In this paper the development and implementation of a CSS is outlined using the Building Block Strategy (BBS) as an example (BBS represents a convergent synthesis in which the target is made out of two structures, i.e., building blocks, coming from two starting materials). The strategy is developed under the philosophy that it is defined as generally as possible and all the intermediate chemical objects, concepts and data are derived from a minimal amount of information to be found in a chemical databank in a preprocessing stage. At RISC-Linz we have developed a chemical expert system (written in LISP) for chemical databank analysis and this was used to generate all data objects for a prototype synthetic planning system using BBS.