Synthese und Struktur Phenyl-substituierter Bicyclo[3.3.1]nonene

✍ Scribed by Quast, Helmut ;Knoll, Katja ;Peters, Eva-Maria ;Peters, Karl ;von Schnering, Hans Georg

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 621 KB
• Volume: 1993
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.1993199301123

✦ Synopsis

Synthesis and Structure of Phenyl‐Substituted Bicyclo[3.3.1]nonenes

Addition of one mole of phenyllithium to bicyclo[3.3.1]nonane‐2,6‐dione (5) affords the hydroxy ketone 6 besides small amounts of the known diol 7. Dehydration of this mixture by sulfuric acid in acetic acid yields the unsaturated ketone 8 and the diene 1 which are separated by chromatography. Wolff‐Kishner reduction of 8 furnished the hydrocarbon 2. In the same way, the known ketones exo‐ and endo‐10 are converted into 4. The preferential formation of the less stable endo‐10 is interpreted in terms of the relative stability of the conformations required in the intramolecular aldol reaction of diketone 9. The conformations of 4, 8, exo‐ and endo‐10 are determined by X‐ray diffraction analyses. Vicinal proton coupling constants are calculated from torsional angles and compared to those determined in solutions by high‐field NMR spectroscopy.