Octacarbonyldicoblat‐Inauced (1,3) H Shits in 1‐Methylallenecarboxylates and Allenic Lactones

This is the authors' abstract. We don't add key points for this paper.

The allenecarboxylates 1a,b and allenic lactones 4a,b undergo thermally induced (1,3) H Shifts in the presence of Co2(CO)8. The non‐isolated 1,3‐dienes 2a,b react further affording the Diels‐Alder Adducts 3a,b Scheme 1 in high yields. These adducts were not formed in the case of the 2‐vinybutenolides 5a,b. On irradiationin the presence of Co2(CO)8 or Mn2(Co)10, the studied allenes reacted in a different manner, yielding either cyclization products 7 and 8 (Scheme 3) or products 9 and 10, formed via H abstracton and solvent addition (Schemes 4 and 5).