Oxidation of bis(2-hydroxy-1-naphthyl)methane (4a) with 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) has been shown to give the novel compounds, cis-and trans-dispiro(naphtha1ene-1,2'(1'H)-naphtho[2,1-b)pyran-3',1 "-naphthalene}-2(1 H),2"(1 "H)-dione (1 2a) and (13a) together with the quinone methide dimer (6a) and the spiroketone (5a). Compounds (12a) and (13a) were characterised on the basis of their spectral properties and the structures were finally confirmed by an Xray crystal structure analysis of (1 2a). Hydrogenation of compounds (I 2a) and (1 3a) has been shown t o give the dihydroxy compound (14) via CC bond cleavage. An alternative synthesis of the dispironaphthalenones (12a) and (13a) was achieved by oxidation of the dihydroxy compound (14), prepared by an independent method. The generality of the oxidation of bisnaphthols of type (4a) to give novel products of the type (1 2a) and (13a) has been shown by studying the oxidation of the variously substituted bisnaphthols (4b-d,f) with DDQ. A mechanism has been proposed invoking the intermediacy of the quinol ethers (22) and (24).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.