(3R,4S)-3-phenyl-1-[(R)-1-phenylethyl]-4-[(R)-1-phenylethyliminomethyl] azetidin-2-one.

The configuration of the chiral ring atoms of the title compound, C26H26N2O, obtained in an enantioselective synthesis, has been established relative to the known R configuration of the α-methyl­benzyl moieties. The crystal packing involves a two-dimensional network of C—H⋯π interactions between the aromatic rings.