[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is an alkane that is propane substituted by a methyl group at position 2. It has a role as a food propellant and a refrigerant. It is an alkane and a gas molecular entity."}, {"from": "gpt", "value": "[C][C][Branch1][C][C][C]"}]