Oxidative Cyclodimerization After Tandem Cyclization of Dehydrobenzo[14]annulenes Induced by Alkyllithium

After eight: Reactions of dehydrobenzo[14]annulenes induced by the addition of n-butyllithium led to the discovery of an unprecedented oxidative cyclodimerization, which forms eight-membered ring products in up to 30 % yield. The product contains two indeno[2,1-a]fluorene components connected by a single and a double bond, which result from three transannular bond formations.