No longer just analytical: Previously, (2R,3S)-isocitric acid (1), a component of the citric acid cycle, had not been available on a preparative scale. A new route to this acid on a kilogram scale combines a biotechnological formation through fermentation from sunflower oil with a chemical separation process. In a variety of transformations into further chiral derivatives, 1 is established as a valuable new member of the chiral pool (see scheme).