含有 0.02% 至 0.15% BHT Contains 0.02%-0.15% BHT Application： Cycloheptatriene can be used as a reactant to synthesize: 2-Hydroxyazulene via [2+2] cycloaddition reaction with dichloroketene, and subsequent ring expansion reaction with diazomethane. 7-Alkyl-bicyclo[4.2.1]nona-2,4,7-trienes by cobalt catalyzed [6+2] cycloaddition with terminal alkynes. (3,5-Cycloheptadienyl)diphenylphosphine ligand by reacting with diphenylphosphine.