Synthesis of a Bicyclo[2.2.1]heptane Skeleton with Two Oxy-Functionalized Bridgehead Carbons via the Diels-Alder Reaction.

We describe a synthetic method for a bicyclo[2.2.1]heptane skeleton with two oxy-functionalized bridgehead carbons. This method involves an intermolecular Diels-Alder reaction using 5,5-disubstituted 1,4-bis(silyloxy)-1,3-cyclopentadienes, the diene structure of which has never been synthesized. Furthermore, the intramolecular Diels-Alder reaction using a diene bearing a dienophile moiety at the C-5 position can provide a tricyclic carbon framework that includes the bicyclo[2.2.1]heptane skeleton. The novel bicyclo[2.2.1]heptane derivatives could be utilized as versatile building blocks for organic synthetic chemistry.