Reaxys includes dynamic synthesis planner to design the optimum synthesis route and multi-step reaction tools to identify precursor reactions underlying synthesis of target compounds. Searchable by structure, formula, and reaction.
Organic Syntheses includes detailed, reliable and peer-reviewed procedures for the synthesis of organic compounds.
Science of Synthesis (Houben-Weyl methods of Molecular Transformations) contains extensive review chapters on methods of organic synthesis, with full experimental procedures and background information. Browsable by a hierarchical table of contents as well as searchable by structure and keyword.