Direct observation of a thermal ring-walk rearrangement in a spironorcaradiene system
Abstract
At 100 °C in toluene, cis-2′-trifluoromethyl-spiro [acenaphthene-1,7′-norcaradiene]-2-one (1; X = CF3) interconverts with its 3′-trifluoromethyl-substituted isomer (2; X = CF3), this being the first directly observed example of a degenerate ring-walk rearrangement for a norcaradiene with a spiro-ring system attached at C-7.