Generation and Reactions of Pentacyclo[4.3.0.0^2,4.0^3,8.0^5,7]non-4-ene

Abstract

The highly pyramidalized alkene, pentacyclo[4.3.0.0(2,4).0(3,8).0(5,7)]non-4-ene (9), has been generated via treatment of 4,5-diiodopentacyclo[4.3.0.0(2,4).0(3,8).0(5,7)]nonane (12) with n-butyllithium and tert-butyllithium. The title alkene has also been trapped as its Diels-Alder adduct with 1,3-diphenylisobenzofuran, 2,5-dimethylfuran, and spiro[2.4]hepta-4,6-diene. Products resulting from alkyllithium addition to the pyramidalized double bond of 9 have been isolated and fully characterized spectroscopically. The geometry, olefin strain energy, heat of hydrogenation, and relative HOMO/LUMO energies of 9 have been obtained by ab initio calculations at the MP2 and B3LYP levels using the 6-31G* basis set.

New polycyclic dual inhibitors of the wild type and the V27A mutant M2 channel of the influenza A virus with unexpected binding mode

“…In order to explore other polycyclic scaffolds to assess their potential as M2 channel blockers, we also synthesized a second small set of compounds. Taking known diester 13 as the first building block [37], a basic hydrolysis was performed upon this molecule to obtain diacid 14 in 86% yield. Unfortunately, we could not reproduce the photochemical reaction of 14 described in the literature to afford polycyclic structure 15 Página 6 de 53 [37], even though the reaction was also attempted with the diester 13 and the anhydride of diacid 14.…”

“…Taking known diester 13 as the first building block [37], a basic hydrolysis was performed upon this molecule to obtain diacid 14 in 86% yield. Unfortunately, we could not reproduce the photochemical reaction of 14 described in the literature to afford polycyclic structure 15 Página 6 de 53 [37], even though the reaction was also attempted with the diester 13 and the anhydride of diacid 14. The synthesis was pursued with the hydrogenation of 14 at high pressure of hydrogen to furnish saturated diacid 16 [38] as the single endo-stereoisomer, which was confirmed with the X-ray diffraction analysis of a subsequent derivative.…”

Generation and Reactions of an Octacyclic Hindered Pyramidalized Alkene

“…Following our previous efforts, 5,18,20 in this study we report the generation of octacyclo[10.6.1.0 1,10 .0 3,7 .0 4,9 .0 8,19 .0 11,16 .0 13,17 ]nonadeca-5,8,14-triene (27), a hindered pyramidalized alkene, by using standard procedures from a diiodide precursor.…”

“…Diiodooctacyclo[10.6.1.0 1,10 .0 3,7 .0 4,9 .08,19 .011,16 .013,17 ]nonadeca-5,14-diene 38.a) Preparation of a potassium cyclopentadienide THF 0.2 M solution. In a 10 mL flask, KH (30% in mineral oil, 134 mg, 1.00 mmol) was washed with anhydrous THF (5 × 5 mL) under an Ar atm.…”

Non-Deprotonating Methodologies for Organolithium Reagents Starting from Non-Halogenated Materials. Part 2: Transmetallation and Addition to Multiple Bonds

“…non-4-ene(86) was reported[55]. The carbolithiation of various terminal non-functionalised alkenes (such as propene, isobutene, 1-octene, methylenecyclopentane) was performed with the dianions derived from biphenyl, Reagents and conditions: (i) Bu n Li (1.9 eq), THF, -78 ºC; (ii) H2O; (iii) [Me2N=CH2] + I -, MeCN, reflux; (iv) HCl, MeOH.…”