Abiraterone dimer impurity

C[C@@]12C (=C (C[C@]1 ([C@]3 ([C@] (CC2) ([C@]4 (C) C (=CC3) C[C@@H] (O) CC4) [H]) [H]) [H]) C=5[C@]6 (C) [C@@] (CC5) ([C@]7 ([C@] (CC6) ([C@]8 (C) C (=CC7) C[C@@H] (O) CC8) [H]) [H]) [H]) C=9C=CC=NC9