Synthese von Bicyclo[3.3.o]oct‐1(5)en‐2‐on aus Cyclohexanon

Synthesis of Bicyclo[3.3.0]oct‐1(5)en‐2‐one from Cyclohexanone Treatment of 2‐nitrocyclohexanone ( 2 ) with acrylaldehyde yielded in the presence of tetrabutylammonium fluoride the bicyclic product 5 , which was oxidized to the nitro‐diketone 3 . The conversion of 3 to the title compound 1 was achieved in the nearly quantitative yield under unusual conditions: K 2 CO 3 /H 2 O and H 2 SO 4 . Compound 3 , was also converted to 1 (stepwise and one‐pot reaction, respectively) by treatment with 1. NaOCH 3 , 2. TiCl 3 , and 3. H 2 SO 4 ( Scheme ).