Regioselectivity in the ring opening of 2-alkylcyclopropylmethyl radicals: the effect of electronegative substituents

Abstract

The regioselectivity of the ring-opening of the trans-2-alkylcyclopropylmethyl radical A to give the primary alkyl radicals B, or the secondary alkyl radicals C, has been investigated, where the groups R [graphic omitted] and/or CXY carry electronegative substituents. All these reactions gave principally the secondary alkyl radicals C, whereas, in the absence of electronegative substituents, ring-opening occurs in favour of the primary alkyl radicals B. This regioselectivity is interpreted in terms of the frontier orbital interactions which are involved.