Synthesis and conformational study of 1,1′-ethano-9-9′-bifluorenyl. Anti and gauche conformers of a 9,9′-bifluorenyl derivative and chair and twist conformers of a dibenzo-1,5-cyclooctadiene derivative

✍ Scribed by Yee-Hing Lai; Siok-Mun Lee; Soo-Ying Lee; Manyin Yi

• Book ID: 104203896
• Publisher: Elsevier Science
• Year: 1993
• Tongue: French
• Weight: 702 KB
• Volume: 49
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)86322-5

✦ Synopsis

Abe&W: A Hofmann-type elimhMion of the sulphonum salt ( ) under basic amdftfons led to the mation of a noovel o-xylylene derivative ( ) which dimedzed regiose/eotive/y to give the MuorenyUdibenw-1,5cydooctad rene derivative (3). The reaotion is shown to be kinetically oonWled and non-oonoetted. The two dgid oo&mers @a) and ( ) were oharaotedsed by their 'H NMR spectra and they rqmseni mqeoffvely Um fitst obsetved exampkx of an anii bkorenyl dedvative and a twist dibenzo-1.5-oyol~ne dedvatfue. A semiempidcal molecular o&M PM3 oakMation sulrported the observed results. Dynamic 'H NMFI studies indioated an intezenvemion process @a) * ( ) at higher temperatures inWving a oonfomWonal banfer estimated at 65.2 kJ mot'.