Abstract: Pyrolysis of 3-methylfurfuryl benzoate gives a 21% yield of 3-methyl-4- methylenecyclobutenone and a 24% yield of 4H, 5H, 9H, lOH-~ ycloocta [1, 2-b: 6, 5- bldifuran (8), the head-to-head,[4+ 41 dimer of 2, 3-dimethylene-2, 3-dihydrofuran (6). A similar pyrolysis of 2-methyl-3-furylmethyl benzoate (10) gives 8 in 51% yield. Low- temperature'H and" C NMR spectral studies show that 6 is the intermediate in the ...