THEORETICAL EVIDENCE FOR NONPLANAR CYCLOPROPYLCARBINYL CATIONS - EFFECT OF ORBITAL DISTORTION ON ENDO AND EXO SOLVOLYTIC PRODUCT RATIOS

Theoretical evidence based upon ab initio molecular orbital calculations is described which provides an explanation for the predominant formation of endo tricyclic solvolytic products derived from the tricyclo[3.3.0.02-8]octan-3-y] cation and related carbenium ions. A theoretical rationale is presented which invokes angular distortion and a nonplanar cationic center in the carbenium ion intermediate. The above arguments are based upon a comparison of the relative energies involved in the calculated rotational barrier and sp2 to sp3 rehybridization of methylcyclopropylcarbinyl cation. © 1979, American Chemical Society. All rights reserved.