Abstract: Spiro [4.4] nonatetraene (1) was prepared for the first time by a relatively direct synthesis starting from allyl bromide and diethyl malonate. Spiro [4.4] nona-l, 3, 7-triene (2) was obtained by a new route, starting from cyclopentadienide anion and 4, 5-di (bromomethyl)-2, 2-dimethyl-l, 3-dioxolane (16). Comparison of the spectral and chemical properties of 1, 2, and spiro [4.4] nona-l, 3-diene (10) revealed significant effects of ...
![spiro[4.4]nona-2,7-diene-4,9-dione Structure](https://image.chemsrc.com/caspic/465/39190-51-7.png)
