[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is a 3-oxo-Delta(4) steroid and a C21-steroid. It derives from a hydride of a pregnane."}, {"from": "gpt", "value": "[C][C][C@H1][C][C][C@@H1][C@@][Ring1][Branch1][Branch2][Ring1][#Branch1][C][C][C@H1][C@H1][Ring1][=Branch1][C][C][C][=C][C][=Branch1][C][=O][C][C][C@][Ring1][O][Ring1][#Branch1][C][C]"}]