1 An Overview of Cinchona Alkaloids in Chemistry

Cinchona alkaloids (Figure 1.1), isolated from the bark of several species of cinchona trees, are the organic molecules with the most colorful biography [1]. Their history dates back to the early seventeenth century when they were first introduced into the European market after the discovery of the antimalarial property of cinchona bark and the subsequent isolation of its active compound, quinine, by Pierre-Joseph Pelletier and Joseph Bienaime Caventou in 1820. Since then, cinchona alkaloids (especially, quinine) have played a pivotal medicinal role in human society for over 300 years. Approximately 700metric tons of cinchona alkaloids is now extracted from the bark of Cinchona ledgeriana annually. Nearly half of this is used in the food and beverages industry as a bitter additive, and much of the remaining quinine and quinidine is used as an important antimalarial drug and muscle relaxant compound and as a cardiac depressant (antiarrhythmic), respectively. The role of cinchona alkaloids in organic chemistry was firmly establishedwith the discovery of their potential as resolving agents by Pasteur in 1853, which ushered in an era of racemate resolutions by the crystallization of diastereomeric salts [3]. Today