N. Ouvrard et al., STEREOCHEMISTRY OF THE CARROLL REARRANGEMENT - STRUCTURE OF R)-2-[(1R,5R)-5-METHYL-2-OXOCYCLOPENTYL]-PROPIONIC ACID, C9H14O3()), Acta crystallographica. Section C, Crystal structure communications, 50, 1994, pp. 624-625
The configurations at the three chiral centres are R, R and R. The two
substituents of the almost planar cyclopentanone are trans and the C2
-C6-C10-C11 torsion angle is - 79 (1)-degrees.