Chiaki Kuroda, Hiroshi Sumiya, Atsushi Murase and Akira Koito
6-Methylbicyclo[4.3.0]non-8-en-7-one was synthesized by FeCl3-induced tandem Nazarov cyclization–rearrangement of 4-cyclopentylidene-5-trimethylsilylpent-1-en-3-one, via 7-methyl-1-methylenespiro[4.4]nonan-2-one as intermediate.