| Abstract: | The title compound, (7R,8S)‐7,8‐dihydroxy‐3,7‐dimethyl‐6‐oxo‐7,8‐dihydro‐6H‐isochromene‐5‐carbaldehyde, C12H12O5, is a trans‐vicinal diol. Of the two fused rings, which lie approximately in the same plane, the pyran ring is almost perfectly planar, while the cyclohexenone ring adopts a slightly distorted half‐chair conformation. The crystal packing is dictated by two strong intermolecular O—H⃛O interactions, one involving hydroxy and keto groups, the other involving two hydroxy groups. Molecules are linked together through twofold axes, forming zigzag ribbons extended along the a axis. |
