Reactions of vinylidenecyclopropanes with xanthydrol and xanthene

Vinylidenecyclopropanes undergo ring-opening reactions with xanthydrol in the presence of BF3·OEt2 or with xanthene in the presence of DDQ at 0 °C in 1,2-dichloroethane to give the corresponding conjugate triene derivatives in moderate to good yields. Plausible reaction mechanisms have been discussed on the basis of previous literature and the control experiments. The further transformation of these trienes has been disclosed in DCE in the presence of BF3·OEt2 along with a plausible reaction mechanism.