?-Facial Selectivity in Diels-Alder Reactions of Hexacyclo2,11.04,9.04,14.09,13>pentadeca-5,7-diene-3,10-dione

Article abstract of DOI:10.1021/jo00230a014

The reactions of the title diene (2) with olefinic dienophiles occur exclusively by attack on the carbonyl-bearing face of the diene component of 2, while other dienophiles (benzyne, acetylenes, and azo compounds) exhibit mixed ?-facial selectivities.X-ray crystal structures of the diene 5 and the diethyl azodicarboxylate adduct 47, refined to conventional R values of 3,8percent and 4.0percent, respectively, are also reported.