3,5a,9-Trimethyl-8-(2-phenylhydrazin-1-ylidene)-4,5,5a,9b-tetrahydro-3aH,8H-naphtho[1,2-b]furan-2(3H)-one

The title compound, C(21)H(24)N(2)O(2), is a phenyl hydrazine derivative of the well known anthelminthic agent α-santonin, which is composed of three fused rings (benzodieneone, cyclo­hexane and γ-lactone). The cyclo­hexa­dienone ring adopts a boat conformation, the cyclo­hexane ring is in a chair conformation and the trans-fused γ-lactone ring adopts a C-envelope conformation. In the crystal, mol­ecules are linked by N—H⋯O and C—H⋯O hydrogen bonds, forming chains along the a axis.