The assignment of the long-standing problem of the stereochemistry of
cis-2,5-dibromocyclopentanone has been performed by stereoselective re
duction into cis, cis-2,5-dibromocyclopentanol, conversion of the latt
er alcohol into the 4-nitrobenzoate ester, and following H-1 NMR and X
-ray crystallographic-analysis.