Anthracene homologs, synthesis

Aminophenols from anilines, 35, 2 Anhydrides of aliphatic dibasic acids, Friedel-Crafts reaction with, 5, 5 Anion-assisted sigmatropic rearrangements, 43, 2 Anthracene homologs, synthesis of, 1, 6 Anti-Markownikoff hydration of alkenes, 13, 1... 

Anthracene homologs can also be prepared in this way, by using derivatives of cyclohexadiene. Further, 1,4-naphthoquinone can be used as starting material (for a single diene synthesis) and the ethylene bridge may be substituted without destroying the ability of the product to split off the ethylene derivative. 

The synthesis of still higher benzocyclopropene homologs by the dichlorocarbene route was unsuccessful. Thus, when the precursor of l//-cyclopropa[/t]anthracene was treated with base under the usual conditions, only 1-chloromethyl- (5a) or 1-rm-butoxymethylanthracenc (5b) in a ratio as a function of the base concentration were isolated. Similarly, twofold dehydrochlorination of the precursor, which should lead to 3,8-dihydrocyclopropa[h]anthracene, gave only 1-methylanthracene (6), and the analogous elimination in the cyclopropa[a]anthracene series afforded no cycloproparene. " ... 

Particular attention has been paid to hnear PAHs composed of laterally annelated benzene rings called acenes. Among the acenes, the lower homologs are referred to as oligoacenes. The oligoacenes from benzene to anthracene can be extracted from crude oil, coal, and coal tar, while those larger than anthracene can be obtained only by multistep synthesis [5]. In this chapter, we will focus on the derivatives... 

---