Catalyst-controlled divergent synthesis of 2,8-dioxabicyclo[3.3.1]nonanes and benzo[ c ]chromen-6-ones

A catalyst-controlled divergent synthesis of 2,8-dioxabicyclo[3.3.1]nonanes and benzo[ c ]chromen-6-ones from easily accessible 4-hydroxy-6-methyl-2 H -pyran-2-one and ortho -hydroxychalcones was reported.