Synthese von Benzofulvenen und Dibenzofulvenen über 1-Chloralkyl-acetate

Synthesis of benzofulvenes and dibenzofulvenes via 1-chloroalkyl-acetates 1,2-Benzofulvene (6a) and 1,2,3,4-dibenzofulvene (7a) as well as the corresponding 6-methyl- and 6-phenyl-derivatives are prepared by reaction of sodium indenide and sodium fluorenide with 1-chloroalkyl acetates (3) , followed by elimination with KOC(CH₃)₃. The over-all yields are comparable with the results of the fulvene series and are in most cases considerably higher than the yields of the Thiele-method.