(5S*,6R*,7R*)-6-Formyl-5-phenyl-7-propyl-perhydro-pyrazolo[1,2-a]pyrazol-1-one.

The title compound, C16H20N2O2, was obtained by catalytic asymmetric cyclo­addition of trans-3-propyl­acrolein with 1-benzyl­idenepyrazolid-3-one betaine. There are two symmetry-independent mol­ecules in the asymmetric unit. In both mol­ecules, the two five-membered heterocyclic rings adopt envelope conformations.