Bridged [14]Annulenes with a Phenanthrene‐Perimeter:anti‐1,6:7,12‐Bismethano[14]annulene

Abstract

Pure Appl. Chem. 58 (1986) 15; b) the same holds for the bridged [14]annulenes with "azupyrene perimeter" (annelated systems of two azulene

Total Synthesis and Establishment of the Stereochemistry of Spiniferin-1, a Rare Planar Chiral Marine Natural Product with a 1,6-Methano[10]annulene Skeleton

“…With the two enantiomers of spiniferin-1 in hand, the stability of the planar chirality was studied. Consistent with the reports of Vogel and co-workers, 17 the planar chirality proves to be stable under neutral conditions (Table 1). No racemization was observed when the chiral samples were placed at 0°C for several months or at elevated temperature (60°C) for 1 hour.…”

Structural Aspects of Aromaticity

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6 Syn ( 1 ) and anti ( 2 ) conformers of bridged [14]annulene. (Reprinted with permission from ref . Copyright 1986 Wiley-VCH Verlag GmbH.

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Annulenes, 1980–2000

“…105 The 1,6:7,12-dimethano [14]annulenes 63 and 64 were prepared in 1986 by multi-step procedures using 1,6disubstituted cycloheptatrienes as starting materials. 106, 107 The syn-isomer 63 is weakly diatropic whilst the anti-isomer 64 is atropic; the valence isomer shown in 64 represents the major constituent. The NMR spectrum of 63 indicates that, although the peripheral electronic system is delocalised, the Kekulé form shown in 63 is the major contributor.…”