rac-Diethyl 9-hy-droxy-9-methyl-7-phenyl-1,4-diaza-spiro-[4.5]decane-6,8-dicarboxyl-ate.

The title mol-ecule, C(21)H(30)N(2)O(5), is chiral with four stereogenic centres. The crystal is a racemate and consists of enanti-omeric pairs with the relative configuration rac-(6S*,7R*,8R*,9S*). The ethyl fragment of the eth-oxy-carbonyl group at position 6 is disordered in a 0.