The title compound, C12H16O6, prepared by a standard synthetic method, was
determined by single-crystal X-ray crystallography to exist with a cyclopro
pane ring fused to a cyclopentene ring. Comparison of the unit-cell dimensi
ons and space group of this material with those of a crystal of the same ma
terial prepared using a route involving pig liver esterase hydrolysis shows
them to be identical.