86814-58-6Relevant articles and documents
Reactions of trans-Cyclooctene and of 7-Methoxy-1,3-dioxa-5(E)-cyclooctene with Allenes and with Chlorsulfonyl Isocyanate. Synthesis of the First trans-Annulated Methylenecyclobutanes. Reaction of Allene as an Ene-Component.
Jendralla, Heiner,Laumen, Kurt
, p. 2136 - 2164 (2007/10/02)
trans-cyclooctene (1) exhibits -cycloadditions with allene and with 1,1-dimethylallene in the temperature range 120 - 150 deg C, with methoxyallene at 90 - 100 deg C.The more strained 7-methoxy-1,3-dioxa-5(E)-cyclooctene (17) reacts at as much as 50 deg C lower temperature, even then suffering concurrently extensive dimerization.All the cycloadducts obtained are trans-annulated.Unsymmetrical allenes react preferentially at the more highly substituted double bond.Confronted with the enophilic trans-olefins1 and 17, allene, but not 1,1-dimethylallene, behave as an ene-component, besides the -cycloaddition.In the cycloadducts of the unsymmetrical trans-olefin 17 the exocyclic double bond is mainly turned away from the methoxy group.The reaction of trans-cyclooctene with 1,2-cyclononadiene at 90 - 100 deg C produces 1:2- and 2:2-cycloadducts (64, 65).At 0 deg C chlorosufonyl isocyanate cycloadds to trans-cyclooctene utilizing its C=N bond (-> 46).
