I. Kinetic and mechanistic study of the [4+4] dimerization of 2,3-dimethylene-2,3-dihydrofuran; II. Preparation of 2,3-dimethylene-2,3-dihydrobenzo[b]furan by the flash vacuum pyrolysis of 2-methyl-3-benzo[b]furylmethyl benzoat; III. Reaction of 2,3-dimethylene-2,3-dihydrofuran with triplet oxygen