Flash vacuum pyrolysis of 2-(2-vinylstyryl)furan derivatives via electrocyclization followed by dehydrogenation will give 2-(2-naphthalen-2-yl)furan analogues, on the other hand, FVP of 2-(2-vinylstyryl)furan derivatives via electrocyclization followed by [1,5]-H shift will give 3-(2-furyl)-1,2-dihydronaphthalene analogues. FVP of 2-[2-(4-methoxyphenyl)vinyl]benzo[b]thiophene gave three products: trans-4-(2-benzo[b]thiophen-2-ylvinyl)phenol, benzo[b]naphtha[1,2-d]thiophen-2-ol and 1H-6-thiacyclopenta[c]fluorene.