α-Naphthyl Phenyl Pinacols

Treatment of α-naphthyl phenyl ketone with Zn/acetic acid gives racemic α-naphthyl phenyl pinacol [1,2-di(1-naphthyl)-1,2-diphenylethane-1,2-diol], C₃₄H₂₆O₂, but reaction with Mg/MgI₂ gives a product which proves to be not a pinacol, but a tricyclic compound (with four chiral centers, formed by addition at the 2-position of one of the naphthalene groups), racemic 5-(1-naphthyl)-3,5-diphenyl-4-oxatricyclo [7.4.0.0^2,6]trideca-7,9,11,13-tetraen-3-ol, C₃₄H₂₆O₂. The aromatic ring in this tricyclic compound is planar, but the other six-membered ring, and the five-membered furano ring, are non-planar. Bond lengths and angles in both molecules correspond to the molecular formulations. In both structures the OH groups are involved in only weak intermolecular interactions.

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