The Adamantane Rearrangement of 1,2-Trimethylenenorbornanes. III. AlBr3-catalyzed rearrangement to 2,6-trimethylenenorbornane

From treatment of D-labelled 1, 2exo-, 1, 2endo- and 2endo, 6endo-trimethylene-norbornane ( 1, 2 and 3 , resp.) with aluminum bromide in carbon disulfide, the evidence is gained that a degenerate rearrangement is involved in the admantane rearrangement of both 1 and 2 to 3 .