Origins of the regioselectivity of cyclopropylcarbinyl ring opening reactions in bicyclo [n.1.0] systems

Abstract

Addition of ·CCl₃ radicals to sabinene 1(R¹= Prⁱ) and a related bicyclo [4.1.0] derivative in BrCCl₃ results in kinetic trapping of the exo ring opened intermediate but in CCl₄ as solvent the major products are derived from the thermodynamically more stable endo radical; the radical and cationic regioselectivities are related to the features of a PM3 SCF-Mo orbital correlation diagram.