Planarisierung von tetrakoordiniertem Kohlenstoffatom. Synthese des überbrückten all‐cis‐[5.5.5.5]Fenestrans 13‐Oxapentacyclo[5.5.2.1^1.7.0^4,15.0^10,15] pentadecan‐14‐on

Abstract

Einleitung. - ') Formel 11 ist beziiglich der Konfiguration am zentralen C-Atom als Fischer-Projektion dargestellt (vgl. hierzu 9 und 10).

Three-Dimensional Hydrocarbon Cores Based on Multiply Fused Cyclopentane and Indane Units: Centropolyindanes

“…Bridgehead functionalization has been achieved not only with the lower congener 18 but also, albeit with less diversity, with the higher congener 25 . An all- cis -[5.5.5.5]fenestrane tetraketone ( 26 , “stauranetetrone”) is known 58-61 in analogy to triketone 21 in the triquinacene series, − to name only one of the numerous derivatives of the homocyclic [5.5.5.5]fenestranes. − The heterocyclic all- cis -[5.5.5.5]-1-azafenestrane ( 27 ) has been synthesized recently . Experimental access to derivatives of the strained cis , cis , cis ,trans -[5.5.5.5]fenestrane 28 has been reported, , and extended studies have been performed on the energetics and geometries of the various even more strained stereoisomers in the [5.5.5.5]fenestrane series; , however, the parent hydrocarbon 28 has remained elusive.…”