2-Methyl-1, 4-naphthaquinones, substituted at C-3 by alkyl, aralkyl, allyl, aryl or halogen groups, react in aqueous ethanolic NaOH to give dehydro-dimers, namely 1, 2-bis (1, 4- naphthaquinon-2-yl) ethanes. The reaction is analogous to the formation of bibenzyls from nitrotoluenes in basic media. In tBuOH containing tBuOK, 3-benzyl-2-methyl-1, 4- naphthaquinone also undergoes oxidation at the benzyl carbon atom to give phthiocol ...