1999 other polycyclic compounds

other polycyclic compoundsQ 1150

34 - 126Synthesis and Base-Induced Epimerization of cis,cis,cis,trans-Tribenzo[5.5.5.6]fenestranes. — [5.5.5.6]Fenestranes (II) and (V) areprepared in the cis,cis,cis,trans-configuration though force field and semiem-pirical MO calculations show that the cis,cis,cis,trans-isomer is more strainedthan the all-cis-isomer by ca. 10 kcalmol−1. Under basic conditions epimer-ization to the all-cis-isomers is observed, cf. compounds (III) and (VI). —(BREDENKOETTER, BJOERN; BARTH, DIETER; KUCK, DIETMAR;Chem. Commun. (Cambridge) (1999) 9, 847-848; Fak. Chem., Univ. Bielefeld,D-33615 Bielefeld, Germany; EN)

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