Studies in the Cycloproparene Series: Electron Transfer Induced Dimerizations of Cyclopropa[b]naphthalene

Abstract

Attempts to characterize the radical anion from 1H-cyclopropa[b]naphthalene (1) by conventional electron transfer techniques has led instead to detection of the pentacene radical anion (10)•- and the pentaphene analogue (11)•- by ENDOR spectroscopy. Reactions of (1) with potassium in tetrahydrofuran on a preparative scale depend upon the surface, and 6,13-dihydropentacene (8), 6,7-dihydropentaphene (9), pentacene (10), 2-methylnaphthalene (12) and 1,2-di(2′-naphthyl)ethane (13) are formed.