42331-06-6Relevant academic research and scientific papers
RING-CLOSURE REACTIONS. XXV. WHY ARE STRAINED SMALL RINGS SO EASILY FORMED IN INTRAMOLECULAR NUCLEOPHILIC SUBSTITUTION REACTIONS?
Casadei, Maria Antonietta,Martino, Alessandro di,Galli, Carlo,Mandolini, Luigi
, p. 659 - 664 (2007/10/02)
The leaving group effect (kBr/kCl) has been determined for two typical series of SN2 cyclisation reactions in the ring size range of 3 to 6 in order to probe the effect of ring strain on transition state structure.The general increase of the magnitude of the leaving group effect on going from the less strained to the more strained ring systems indicates that bond making and bond breaking is significant also in the small ring transition states.The apparent unimportance of strain in the products to the ease of closure of the smallest rings is tentatively explained by the hypothesis that the adverse effect of ring strain is partially offset by a significant reduction of non-bonded interactions in the transition states.
