C. Kuroda et Y. Hirono, SYNTHESIS OF SPIRO[4.5]DECANE RING-SYSTEM THROUGH ALLYLSILANE PROMOTED SPIROANNULATION, Tetrahedron letters, 35(37), 1994, pp. 6895-6896
Spiro[4.5]decane ring system with methylene ketone on five membered ri
ng was synthesized by Nazarov cyclization of alpha-(trimethylsilylmeth
yl)divinyl ketone derivatives.