Chiral silver phosphate catalyzed transformation of ortho-alkynylaryl ketones into 1H-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 1H-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.