Cycloaddition Reaction of 1,4‐Dihydronaphthalene 1,4‐Epoxide with Cyclooctatetraene: Cope Rearrangement in an Adduct

Abstract

The reaction of 1,4‐dihydro‐1,4‐epoxynaphthalene with cyclooctatetraene at 130±5° for 14 days gave the four products 2a,3,3a,4,9,9a,10,10a‐octahydro‐4,9‐epoxy‐3,10‐ethenocyclobuta[b]anthracene (13), 25‐oxanonacyclo[10.10.2.25,9.114,21.02,11.03,10.04,6.013,22.015,20]heptacosa‐7,15,17,19,23,26‐hexaene (14), 5,5a,6,6a,6b,6c,12a,12b,12c,13,13a,14‐dodecahydro‐5,14‐epoxy‐6,13‐ethenocycloocta[3′,4′]cyclobuta[1′,2′:3,4]cyclobuta[1,2‐b]anthracene (15) and bis‐adduct 16. The structures of the products were determined by spectroscopic methods. It was observed that adduct 14 undergoes a Cope rearrangement. The Cope rearrangement of this adduct was investigated in the temperature range of −85° to 100° by NMR spectroscopy.

Lewis Base‐Catalyzed Cycloaddition of Heterocyclic Alkenes with 2,2,2‐Trifluorodiazoethane (CF3CHN2): Access to Trifluoromethylated Pyrazolines and Pyrazoles

“…Due to the angle strain and the proximal heteroatom coordination, heterobicyclic alkenes are versatile synthetic building‐blocks for the construction of complex cyclic frame works in various types of organic transformations including metal‐catalyzed cycloaddition reactions, [10a–g] metal‐catalyzed C−H addition and annulations, [10h–j] ring opening reactions [10k–l] . Oxa ‐ and aza‐ bicyclic alkenes, such as oxa ‐ and aza ‐benzonorbornadienes, have been recognized as useful building blocks in molecular architecture as they can serve as general templates to create highly substituted ring systems [11] .…”

Synthesis and some enzyme inhibition effects of isoxazoline and pyrazoline derivatives including benzonorbornene unit

“…As shown in the text, these adducts should be obtained by exo-cycloaddition of intermediate nitrile imine to 4 because of exo selectivity. [3,[14][15][16][17] Hydrogens in the five-membered rings resonated in the range of 4.55-3.88 ppm as d (J = 9.4 or 9.2 Hz).…”

An intermolecular Diels-Alder cycloaddition under various condition between 1,3-cyclohexadiene and 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate

“…[1][2][3][4][5][6][7] Cycloaddition occurs readily if the diene is substituted with electron-donating groups (as -OR, -NR2, etc. ), and the dienophile is substituted with electron-withdrawing groups (as -NO2, -CN, -COR, etc.)…”