Chiral Silver Phosphate Catalyzed Transformation of ortho ‐Alkynylaryl Ketones into 1 H ‐Isochromene Derivatives through an Intramolecular‐Cyclization/Enantioselective‐Reduction Sequence

The transformation of ortho ‐alkynylaryl ketones through a cyclization/enantioselective‐reduction sequence in the presence of a chiral silver phosphate catalyst afforded 1 H ‐isochromene derivatives in high yield with fairly good to high enantioselectivity. An asymmetric synthesis of the 9‐oxabicyclo[3.3.1]nona‐2,6‐diene framework, which has been found in some biologically active molecules, is presented as a demonstration of the synthetic utility of this method.