Preparation of Several 1,5,5,11,11-Pentamethyltricyclo2,6>undecane Derivatives

Article abstract of DOI:10.1246/bcsj.54.1117

1,6-Diketone, available in eight steps from homocamphorquinone, was converted into 1,5,5,11,11-pentamethyltricyclo<6.2.1.0^2,6>undecan-7-one by treatment with potassium t-butoxide and then lithium dimethylcuprate, while α,α-dimethyl-γ-valerolactone, prepared in five steps from homocamphor, was converted into 1,5,5,11,11-pentamethyltricyclo<6.2.1.O^2,6>undec-2-en-4-one by treatment with diphosphorus pentoxide-methanesulfonic acid.