CONFORMATIONAL ASPECTS OF SOME ASYMMETRIC DIELS-ALDER REACTIONS - A MOLECULAR MECHANICS PLUS POLARIZATION STUDY

The MM2 force field, improved by the inclusion of interacting induced dipole (ID) energies, is used to calculate the conformational preferences of three chiral dienophiles: Acrylate of (S)-ethyl lactate (1), N-acryloyl-L-phenylalanine methyl ester (2), and N-acryloyl-L-alanine methyl ester (3). The results obtained agree with the models previously proposed to account for the asymmetric induction obtained in the reaction of these dienophiles with cyclopentadiene.