Semiempirical SCF MO study of ring inversion in 1,1,4,4,7,7-tetramethylcyclononane and trimeric acetone peroxide

An investigation employing the MNDO, AM1, and PM3 semiempirical SCF MO meth ods to calculate structure optimization and conformational interconversion pathways for 1,1,4,4,7,7-tetramethylcyclononane (1) and 3,3,6,6,9,9-tetrame thyl-1,2,4,5,7,8-hexaoxa- cyclononane (trimeric acetone peroxide, (2) has b een undertaken. Both compounds take the symmetrical TBC (D-3) conformation. Compounds 1 and 2 are expected to have chiral stability at room temperatur e as their conformational racemization energies are higher than 80 kJ mol(- 1). (C) 2001 Elsevier Science B.V. All rights reserved.