Diastereoselective Conjugate Radical Additions to ~-Pyrones
Abstract
A convenient protocol for functionalization of ~-pyrones has been developed.
Conjugate radical addition and tandem addition-trapping protocols allowed accessing
highly substituted pyrones in a single operation with high selectivity. Different radical
sources were utilized in the reaction. nOe experiments were performed to confirm the
relative stereochemistry of the substituents in the conjugate addition products. Initial
studies on the enantioselectivity of the reaction were carried out. Unfortunately, the
catalysts chosen for the initial studies did not show any promise regarding
enantioselectivity.