hydrogenated rapidly (within 10 s) to furnish the bridgehead olefins 13b and 12c. The accompanying hydrogenation enthalpies are -220 and -141 kJmol(-1), respectively. Strain energies (SE) and olefinic strains (OS) of a number of bridgehead olefins have been evaluated by DFT calculations; it was concluded that 13b belongs to the class of hyperstableolefins which correlates nicely with its reluctance to undergo
作者:Geerlig W. Wijsman、Willem M. Boesveld、Marcus C. Beekman、Marcel Schreuder Goedheijt、Ben L. M. van Baar、Franciscus J. J. de Kanter、Willem H. de Wolf、Friedrich Bickelhaupt
Diels−Alder reactions with dienophiles, compounds 1 behaved like reactive dienes, adding at positions 8 and 11 of the aromatic ring. Substitution by chlorine, though, reduced the reaction rate; the unsymmetrical dienophile acrylonitrile showed little preference for the two possible regioisomeric adducts 8 and 9. Similarly, compounds 1 were unusually reactive towards acid, and interesting and unforeseen