ABINITIO SCF CALCULATIONS ON THE PHOTO-CHEMICAL BEHAVIOR OF THE 3-MEMBERED RINGS .3. OXIRANE - RING-OPENING

In this paper and the accompanying one the overall thermal and photochemical behavior of oxiranes is theoretically simulated with ethylene oxide as a prototype. An ab initio SCF method (STO-3G basis) followed by a limited CI involving the first 100 mono-and biexcited configurations is used in order to provide a basis for a semiquantitative rationale of the main reactive trends. Primary processes are examined in a first part : ring cleavage by CO bond rupture and different types of CC bond cleavage (the face to face, the conrotatory, and the disrotatory modes). © 1979, American Chemical Society. All rights reserved.