Beschreibung:
<jats:p><jats:bold>Studies in the Synthesis of Helical Naphthoquinone Oligomers, I. — 2,2′;3′,2″‐Ter‐ and 2,2′;3′,2′;3′,2‴‐Quater(1,4‐naphthoquinone)</jats:bold></jats:p><jats:p>2,2′;3′,2′‐Ter(1,4‐naphthoquinone) (<jats:bold>6a</jats:bold>) and 2,2′;3′,2″;3″,2‴‐quater(1,4‐naphthoquinone) (<jats:bold>8a</jats:bold>) are obtained by cooxidation of the phenolic precursors <jats:bold>16a</jats:bold> and <jats:bold>2b</jats:bold>. It is shown, that partially reduced <jats:bold>6a</jats:bold> cyclizes under basic conditions yielding triphthaloylbenzene (<jats:bold>7</jats:bold>); therefore, it is also a possible intermediate of the synthesis of <jats:bold>7</jats:bold> by phenol/quinone addition of <jats:bold>2a</jats:bold> to <jats:bold>1a</jats:bold>. Spectroscopic data suggest that the tetrameric hydroquinonylquinone <jats:bold>8b</jats:bold> is stabilized by hydrogen bonding, forming a helical quinhydron structure.</jats:p>