The Origin of Atropisomerism in 2,2′-Bis((1R,2R,4S)-2-hydroxy-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl)-1,1′-biphenyl: Synthesis, Structure and Energetics

✍ Scribed by Bernd Goldfuss; Frank Rominger

• Publisher: Elsevier Science
• Year: 2000
• Tongue: French
• Weight: 141 KB
• Volume: 56
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(99)01077-7

✦ Synopsis

In the X-ray crystal structure of 2,2 H -bis((1R,2R,4S)-2-hydroxy-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl)-1,1 H -biphenyl (3-R) fenchyl alcohol units induce a R-sense of asymmetry at the biphenyl axis and support intramolecular hydrogen bonds between the hydroxy groups. Computational ONIOM evaluations of 3-R and of its diastereomer with S-biphenyl axis (3-S) reveal a higher stability (Ͼ6 kcal/mol) for 3-R and show how suitable alignments of 1,3,3-trimethylbicyclo[2.2.1]heptane units originate the observed R-biphenyl axis.