Isomerization and functionalization of 2:1 Diels–Alder adducts of cyclopentadiene and p-benzoquinone: Applications to polycycles via ring-closing metathesis and ring-opening metathesis as key steps

• Published in: Tetrahedron letters Vol. 58; no. 13; pp. 1283 - 1286
• Main Authors: Kotha, Sambasivarao, Rao, Nalajala Nageswara, Ravikumar, Ongolu, Sreevani, Gaddamedi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 29-03-2017
• Subjects: Allylation; Cyclopentadiene; Diels–Alder; Isomerization; Metathesis; p-Benzoquinone; Diels–Alder; Cyclopentadiene; p-Benzoquinone; Isomerization; Metathesis; Allylation
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2017.02.039

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•Norbornene derivatives prepared by Diels–Alder reaction undergo ring-opening metathesis.•Simple, efficient and atom economic route has been used to generate polycycles.•Cyclopentadiene and benzoquinone undergo cycloaddition give various bis-adducts.
Five stereochemically different 2:1 Diels–Alder adducts were prepared starting with cyclopentadiene and p-benzoquinone. Separately, these adducts were treated with an excess amount of base and allyl bromide to deliver two different tetra-allylated products. These allyl derivatives gave the corresponding mono-propellane derivatives on metathesis sequence. Five Diels–Alder adducts on treatment with Grubbs ruthenium catalysts delivered the corresponding mono- and di-ring-opened metathesis products. Structures of three functionalized adducts were determined by single-crystal X-ray diffraction studies.