Many of Woodward's syntheses were described as spectacular by his colleagues. Before he did them, some people thought it would be impossible to create these substances in the lab. Woodward's syntheses were also described as having an element of art in them, and since then, synthetic chemists have always looked for elegance as well as utility in synthesis. His work also involved the exhaustive use of the then newly developed techniques of infrared spectroscopy and later, nuclear magnetic resonance spectroscopy. Another important feature of Woodward's syntheses was their attention to stereochemistry or the particular configuration of molecules in three dimensional space. Most natural products of medicinal importance are effective, for example as drugs, only when they possess a specific stereochemistry. This creates the demand for 'stereospecific synthesis', producing a compound with a defined stereochemistry. Woodward was a pioneer in showing how one could conduct reactions that were stereospecific. Many of his syntheses involved forcing a molecule into a certain configuration by installing rigid structural elements in it, another tactic that has become standard today. In this regard, especially his syntheses of reserpine and strychnine were landmarks.