Collect. Czech. Chem. Commun. 2000, 65, 555-560

Helical Phenanthrenes, Part 5. Synthesis of Pentahelicene-7,8-dione via Intramolecular Benzoin Condensation

Anja Modler-Spreitzer, Rainer Fritsch and Albrecht Mannschreck*

Institut für Organische Chemie, Universität Regensburg, D-93040 Regensburg, Germany


The intramolecular benzoin condensation of [1,1'-binaphthyl]-2,2'-dicarbaldehyde (5), followed by oxidation with air, provides a new synthesis of (MP)-pentahelicene-7,8-dione (1). With reference to the original preparation of this quinone via acyloin condensation, its present yield (73% for the ring-closing step) is considerably increased.

Keywords: Benzoin condensation; Helicenediones; Pentahelicene-7,8-dione; Helicenes; Quinones; Binaphthyls; Helicity.

References: 16 live references.