Pi-stacking effect on levoglucosenone derived internal chiral auxiliaries. A case of complete enantioselectivity inversion on the Diels-Alder reaction.

Detailed quantum chemical calculations, experimental evidence, and NMR data rationalize the participation of pi-stacking interaction in the highly asymmetric Diels-Alder reaction using levoglucosenone derived internal chiral auxiliaries, including the appealing effect of inversion of the enantioselectivity by coordination of the substrate with Et 2AlCl.