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
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
Diels–Alder reactions in confined spaces: the influence of catalyst structure and the nature of active sites for the retro-Diels–Alder reaction
作者:Ángel Cantín、M Victoria Gomez、Antonio de la Hoz
DOI:10.3762/bjoc.12.208
日期:——
Diels-Alder cycloaddition between cyclopentadiene and p-benzoquinone has been studied in the confined space of a pure silica zeolite Beta and the impact on reaction rate due to the concentration effect within the pore and diffusion limitations are discussed. Introduction of Lewis or Bronsted acid sites on the walls of the zeolite strongly increases the reaction rate. However, contrary to what occurs
Studies of Diastereoselectivity in Diels−Alder Reactions of (S)<i>S</i>-4a,5,8,8a-Tetrahydro-5,8-methane-2-(<i>p</i>-tolylsulfinyl)-1,4-naphtho- quinones with Cyclopentadiene
作者:M. Carmen Carreño、José L. García Ruano、Antonio Urbano、Miguel A. Hoyos
DOI:10.1021/jo9521209
日期:1996.1.1
compounds 6 and 7 have proved to be adequate rigid models to evaluate the ability of the sulfinyl group to control the diastereoselectivity of the [4 + 2] cycloadditions of cyclopentadiene on the ene-dione moiety. The results of thermal and Lewis acid-catalyzed reactions allowed us to establish that both reactivity and endo/exo selectivity were modulated by the presence of the sulfinyl group, the endo-anti-endo