Fragmentation of cyclobutoxychlorocarbene: the cyclopropylcarbinyl/cyclobutyl cations revisited

Abstract

Abstract Fragmentations of cyclobutoxychlorocarbene ( 13 , k frag = 7.1 × 10 5 s −1 ) and cyclopropylmethoxychlorocarbene ( 14 , k frag = 7.6 × 10 5 s −1 ) in MeCN proceed to tight and distinct [R + OC Cl − ] ion pairs, which collapse to different distributions of cyclopropylcarbinyl, cyclobutyl and allylcarbinyl chlorides. B3LYP/6–31G* calculations support these conclusions, affording computed fragmentation activation energies of 6.4 ( 13 ) and 3.0 ( 14 ) kcal mol −1 . Copyright © 2001 John Wiley & Sons, Ltd.