[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is a member of the class of 2,5-diketopiperazines that is piperazine-2,5-dione in which one hydrogen at position 3 and one hydrogen at position 6 are replaced by isobutyl groups (the 3S,6S-diastereomer)."}, {"from": "gpt", "value": "[C][C][Branch1][C][C][C][C@H1][C][=Branch1][C][=O][N][C@H1][Branch1][Branch2][C][=Branch1][C][=O][N][Ring1][Branch2][C][C][Branch1][C][C][C]"}]