Herein we report a platinum-catalyzed isomerization of cyclopropenes to 1,3-dienes. Diverse dienylated alcohols were obtained in 42-98 % yield. The synthetic potential of the products was demonstrated by their use in Diels-Alder cycloadditions with various dienophiles. Isotope labelling studies provide strong support for a mechanism involving pericyclic [1,5]-σ-bond rearrangement of a vinyl platinum carbene intermediate.