M. Iyoda et al., SYNTHESIS OF PENTACARBONYL(1-OXAZULEN-2-YLIDENE)CHROMIUM(0) AND PENTACARBONYL(1-OXAZULEN-2-YLIDENE)TUNGSTEN(0) COMPLEXES, Tetrahedron letters, 36(21), 1995, pp. 3699-3702
The reaction of tropone or 2-substituted tropone with the anions deriv
ed from methylmethoxycarbene complexes of chromium and tungsten gave p
entacarbonyl(1-oxazulen-2-ylidene)chromium and tungsten complexes.