Flash vacuum pyrolysis (FVP) of aryl propargyl ether 9 produces 2-methylbenzofuran 21, 2H-chromene indanone 22 and benzocyclobutene 23. o-chloro-and bromo-aryl propargyl ethers 10 & 11 resulted mainly in methyl-benzofurans 25, 26 & 29 and 2H-chromene derivative 27. On the other hand, FVP of arylpropargyl ethers with an active substituent at the ortho position of the aryl group 12-15 & 20 has resulted in interesting, unexpected products. All products were analyzed, fully characterized, and identified. Mechanisms are proposed for most of these FVP reactions.