organic compounds
Open access
The title compound, C9H12O5, is a bicyclic lactone, presenting a 2,6-dioxabicyclo[3.3.0]octan-3-one skeleton, which was obtained through an intramolecular lactonization. The bicyclic lactone presents a cis ring-junction and a 1,5-trans-substituted tetrahydrofuran. Both five-membered rings are in twisted envelope conformations with one of the fused C atoms as the flap. The dihedral angle between the mean planes of the bicyclic lactone residue, defined by the dihydrofuran-2(3H)-one and the tetrahydrofuran rings, is 69.5 (2)°. The atoms of the ester chain are coplanar [maximum deviation = 0.013 (2) Å]. The absolute structure was not determined.
organic compounds
Open access
The molecule of the title compound, C11H15NO, contains a cyclohexanone ring, three defined stereocenters and an exocyclic double bond. The crystal structure is the result of a study on the Michael addition reaction of (S)-carvone with sodium cyanide using ionic liquids as the reaction medium and so the absolute configuration is known from the chemistry. The six-membered ring is in a chair conformation.