217454-50-7Relevant academic research and scientific papers
Heterocycle synthesis based on allylic alcohol transposition using traceless trapping groups
Xie, Youwei,Floreancig, Paul E.
supporting information, p. 4926 - 4929 (2014/05/20)
Allylic alcohols undergo transposition reactions in the presence of Re 2O7 whereby the equilibrium can be dictated by trapping one isomer with a pendent electrophile. Additional ionization can occur when the trapping group is an aldehyde or ketone, thus leading to cyclic oxocarbenium ion formation. Terminating the process through bimolecular nucleophilic addition into the intermediate provides a versatile method for the synthesis of diverse oxygen-containing heterocycles. Understanding the relative rates of the steps in the sequence leads to the design of reactions which create multiple stereocenters with good to excellent levels of control.
Intramolecular cyclization of tethered phenyl ketones. Complementary stereochemical results arising from the indium-promoted ring closure of allyl bromides and the fluoride ion-induced desilylation of allylsilanes
Paquette, Leo A.,Mendez-Andino, Jose L.
, p. 9061 - 9068 (2007/10/03)
The intramolecular indium-promoted cyclization of 4'-substituted (Z)- and (E)-7-bromo-5-heptenophenones has been examined in aqueous tetrahydrofuran. In every instance, ring closure occurred to deliver the syn- 2-vinylcyclopentanol exclusively. The corresponding allylsilanes have been prepared as well, and the course of their fluoride ion-induced cyclization was also studied. In these systems, a kinetic bias for formation of the anti- 2-vinylcyclopentanol is observed, although not with the same exclusivity. Accordingly, complementarity in product diastereoselectivity can be realized in purposeful fashion. The data acquired in this investigation suggest that the indium-catalyzed reactions involve intramolecularly coordinated transition states where development of a cis 5/6-bicyclic framework is most energetically feasible. In contrast, the silanes appear to utilize open- chain antiperiplanar transition states. While the latter are not particularly sensitive to double-bond geometry, they are responsive to steric compression involving the aryl group.
