Synthesis of 5-(2-methoxy-1-naphthyl)- and 5-[2- (methoxymethyl)-1- naphthyl]-11H-benzo[b]fluorene as 2,2'-disubstituted 1,1'-binaphthyls via benzannulated enyne-allenes

Abstract

5-(2-Methoxy-1-naphthyl)- and 5-[2-(methoxymethyl)-1-naphthyl]-11H-benzo[b] fluorene were synthesized by treatment of the corresponding benzannulated enediynes with potassium tert-butoxide in refluxing toluene to give benzannulated enyne-allenes for the subsequent Schmittel cascade cyclization reactions. The structures of these two 5-(1-naphthyl)-11H-benzo[b]fluorenes could be regarded as 2,2′-disubstituted 1,1′-binaphthyls with the newly constructed benzofluorenyl group serving as a naphthyl moiety. © 2011 Wang et al; licensee Beilstein.