2,3‐Dicyanobutadiene as a Reactive Intermediate by in situ Generation from 1,2‐Dicyanocyclobutene: 2,3‐Dicyano‐1,4,4a,9a‐Tetrahydrofluorene

2,3-Dicyanobutadiene as a reactive intermediate by in situ generation from 1,2-dicyanocyclobutene: 2,3-dicyano-1,4,4a,9a-tetrahydrofluorene intermediate: 1-Chloro-1,2-dicyanocyclobutane (1) intermediate: 1,2-Dicyanocyclobutene (2) reactant: 131 g. (1.30 moles) of triethylamine product: 2,3-Dicyano-1,4,4a,9a-tetrahydrofluorene (3) reactant: 23.3 g. (0.201 mole) of indene product: 2,3-dicyanofluorene product: 4,5-Dicyanotricyclo-[6.2.1.02,7]undeca-4,9-diene product: 8,9-Dicyano-6b,7,10,10a-tetrahydrofluoranthene product: 3,4-Dicyanobicyclo[4.3.0]non-3-ene product: 1,2-Dicyanocyclohexene product: 1,2-Dicyano-4,5-diphenylcyclohexene product: 1,2-Dicyano-4-butoxycyclohexene product: 1,2-Dicyano-4,5-trans-dichlorocyclohexene product: 1,2-Dicyano-4-(2 -pyridyl)cyclohexene Keywords: annulation, carbocyclic-[6]; cyclization, cycloaddition; elimination, dehydrohalogenation; halogenation, chlorination