Cycloadditions of isobenzofuran to a constrained template bearing neighboring dienophiles

A high yielding synthesis of the pentacyclic diene - dione 1 has enabled investigation of its reactivity as a double dienophile in Diels - Alder [4+2] cycloadditions with isobenzofuran, leading to novel and highly symmetrical three-sided cavitands 3 and 4