[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is a glycol that is 1,4-butanediol substituted at position 2 by a methylidene group. It is a glycol, a primary allylic alcohol and a homoallylic alcohol."}, {"from": "gpt", "value": "[C][=C][Branch1][Ring2][C][C][O][C][O]"}]