2,5-Bis[(Z)-2-nitrobenzenesulfenylmethylene]-3,6-bis(methylene)-7-oxabicyclo[2.2.1]heptane. A versatile reagent for tandem regioselective Diels-Alder reactions
Face Selectivity of theDiels-Alder Additions of Sulfur-Substituted Dienes and Tetraenes Grafted onto 7-Oxabicyclo[2.2.1]heptanes
作者:Jean-Marc Tornare、Pierre Vogel、A. Alan Pinkerton、Dieter Schwarzenbach
DOI:10.1002/hlca.19850680815
日期:1985.12.18
on the nature of the dienophile. It is exo-face selective with bulky dienophiles such as ethylene-tetracarbonitrile (TCNE) and 2-nitro-1-butene and endo-face selective with methyl vinyl ketone, methyl acrylate, and 3-butyn-2-one. In the presence of a Lewis acid, the face selectivity of the Diels-Alderreaction can be reversed. The addition of the first equivalent of a dienophile to tetraene 17 is at