0000000000184245
AUTHOR
Melanie Tschertsche
(1aR,2aS,5aS,5bS)-Perhydro-4H-oxireno[3,4]cyclopenta[1,2-b]furan-4-one
The structure of the title compound, C7H8O3, was determined in the course of our studies of the synthesis of cyclopenta[1,2-b]furan-4-one derivatives. The molecule has four chiral C atoms. The X-ray crystal structure analysis shows the compound to possess an epoxide group with an endo orientation with respect to the lactone group.
(2aRS,3RS,4aSR,6aRS,6bSR)-3-Hydroxy-2a,3,4a,6,6a,6b-hexahydro-1,4-dioxacyclopenta[cd]pentalen-2(5H)-one
The molecular structure of the title compound [enantiomers (VIII) and (VIIIa)], C8H10O4, was determined in the course of our studies on the synthesis of cyclopenta[1,2-b]furan-4-one derivatives. Tricyclic (VIIIa) consists of a planar bridged lactone unit and the two other ring systems in the envelope conformation. It contains five chiral C atoms and was obtained as a racemic mixture. The X-ray analysis showed the compound to possess a half-acetal unit with an endo orientation of the half-acetal ether bridge with respect to the lactone unit.
rac-(3E,3aR,6aR)-3-(Hydroxymethylene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one
The crystal structure of the title compound, C8H8O3, was determined in the course of our studies of the synthesis of cyclopenta[1,2-b]furan-4-one derivatives. The title compound has two chiral C atoms and was obtained as a racemic mixture. It was found to possess a vinylogous acid group with an E configuration at the double bond. The compound exists in the hydroxymethylene and not in the tautomeric carbaldehyde form. The asymmetric unit consists of two molecules.