Höhere, kondensierte Ringsysteme. 6. Mitteilung [1]. NBS‐Dehydrierungen an 9,10‐Dihydrophenanthrensystemen Synthese von [2³] (2,7) Phenanthrenophan‐trien

Abstract

0. Mittellung 11 j (1. X l l . 70) Suvlzmuvy. Thc usefulness of thc 1ou tcmperaturc tlch) tlrogenation by hr-hrornosuccinimide is illustrated in the 9,lU-dihydrophenanthrcne seric. l'hc synthcses of 2,7-tli -chlororncthyl-phenanthrenc, 2,7-rli-hroinornethyl-phenanthrenc and hcxabroino-[ Zs] (2,7) phcnanthrenophane by NBS-dehydrogenation arc described. Debroinination of hexabromo-[Z3j (2,7) phenanthrenophane Icd t o [Z3j (2,7) phenanthrenophanc-triene. The structure of these new compounds was confirnied by NMR.-, UV.and mass spectroscopy.

Non-alternant non-benzenoid kekulenes: the birth of a new kekulene family

“…In 1978, Staab and Diederich made a seminal achievement in the chemistry of aromatic compounds by synthesizing kekulene ( 1 ), the first representative of cycloarene. 2,3 Despite intense attempts by Staab himself, 4 Jenny 5 and others, it had eluded synthesis for many years; as early as 1965, Staab reported the first attempts to prepare 1 , and at the centennial of Kekulé's benzene structure at a German Chemical Society Meeting, it was given the name “kekulene” because it was regarded as a “superbenzene” due to its potential macrocyclic conjugation and planar D 6h symmetric structure. 3 Among several reasons for targeting 1 , the most important was the suggestion by McWeeny that 1 would provide a crucial experimental test of the predictions regarding diamagnetic anisotropy of aromatic systems.…”