Ene Reactions of Tricyclo2,6>hex-1(6)-ene

Article abstract of DOI:10.1016/S0040-4020(01)89892-6

1,6-Dibromotricyclo<3.1.0.0^2,6>hexane 2e has been prepared in 56percent yield by reaction of 1,6-dilithiotricyclo<3.1.0.0^2,6>hexane 2d with 2.5 equiv. of tosyl bromide. 2e proved to be a new source for generating tricyclo<3.1.0.0^2,6>hex-1(6)-ene 1 by reaction with magnesium, with lithium sand, or with tert-butyllithium, as shown by formation of the Diels-Alder adduct 5.Ene adducts of 1 were obtained with alkenes 7a-e, not, however, with allylbenzene.The cis-fixed 1,3-diene 10 and 1 gave rise to a 48percent yield of 11, whereas 10 and 4, the higher homologue of 1, led to a 27percent yield of 14.