The Diels-Alder reactions of the title compounds (1-3) with N-methyltriazolinedione (MTAD) were investigated and determined to proceed with endo stereospecificity. Stereochemical assignment to the adduct derived from 3, viz., 4, was arrived at by a three-dimensional X-ray crystal structure analysis. In the case of 9, the cycloadduct derived from 2, reliance was placed upon diimide redution of its more reactive internal double bond from the exo ...