Abstract: Cyclooctatetraene dianion reacts as a 1, 2-and a 1, Cdicarbanionic reagent with benzaldehyde, acetaldehyde, o-phthalaldehyde, acetone, benzophenone, and fluorenone to give 5, 8-bis (a-hydroxyalkyl)-l, 3, 6-cyclooctatrienes, 7, 8-bis (cu-hydroxyalkyl) bicyclo [4.2. 0loctadienes, and 2, 4, 6, 8-tetraene-l, lO-diols. The bicyclo-[4.2. 0] octadienes and the 2, 4, 6, 8-tetraenediols are apparently formed by isomerization of the initial 7, 8- ...