Abstract: | The title compound, (1R)‐4,7,7‐trimethyl‐3‐oxobicyclo2.2.1]heptane‐2‐endo‐acetic acid, C12H18O3, like its lower homolog, forms carboxyl‐to‐ketone hydrogen‐bonding catemers (Z′ = 2) O⋯O = 2.729 (5) and 2.707 (5) Å, and O—H⋯O = 165 and 170°] with screw‐related components. The two molecules of the asymmetric unit differ slightly in conformation and produce two counter‐aligned hydrogen‐bonding chains, both aligned with the b axis. Close intermolecular C—H⋯O=C contacts exist for the ketone group of one molecule and for both the ketone and carboxyl functions in the other. |