Table 3. Cycloadditions of Other Cyclic 2-Amidodienes.

^aReaction conditions followed those described for entry 5 in Table 1. All are isolated yields.

^bRatios denote endo:exo [a/b:c/d] with the exo-I:exo-II ratio [c:d] shown in parentheses. They are determined using ¹H and/or ¹³C NMR.

^cPMP = p-methoxyphenyl.

^dThis ratio implies a single isomer is observed here.

^eOnly one exo-cycloadduct was seen but unassigned whether it is exo-I or exo-II.