The cycloaddition between protonated glyoxylate imines possessing two chiral auxiliaries, N- (S)-or N-(R)-1-phenylethyl and (−)-8-phenylmenthyl or (+)-8-phenylneomenthyl, and cyclopentadiene is described. The absolute configuration of all adducts formed was unequivocally assigned through NMR, specific optical rotation, and X-ray data of appropriated derivatives. Experimental results confirm the highly exo-selectivity for these ...
[Garcia-Mera, Xerardo; Alves, Maria J.; Goth, Albertino; Do Vale, Maria Luisa; Rodriguez-Borges, Jose E. Tetrahedron, 2013 , vol. 69, # 14 p. 2909 - 2919]