ON THE ORIGIN OF PI-FACIAL DIASTEREOSELECTIVITY IN NUCLEOPHILIC ADDITIONS TO CHIRAL CARBONYL-COMPOUNDS .4. CALCULATED TRANSITION-STATE STRUCTURES FOR THE ADDITION OF NUCLEOPHILES TO 2-METHOXYPROPANAL AND 2-N,N-DIMETHYLAMINOPROPANAL

The transition state structures of the nucleophilic addition of LiH to 2-methoxypropanal and 2-N,N-dimethylaminopropanal have been calculated using ab initio methods at the MP2/6-31G*//3-21G level of theory. The analysis of the theoretical data shows that Coulombic, electronic and steric interactions as well as conformational energies may be dominant for determining the energetically lowest lying transition states.