Acceptor, donor, and captodative stabilization in transition states of 5-hexen-1-yl radical cyclizations

SU Park, SK Chung, M Newcomb

Index: Park, Seung-Un; Chung, Sung-Kee; Newcomb, Martin Journal of the American Chemical Society, 1986 , vol. 108, # 2 p. 240 - 244

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Citation Number: 54

Abstract

Abstract: Rate constants and activation parameters for cyclization of the 6-substituted hex-5- en-1-yl radicals (6-cyano (lb), 6-methoxy (IC), and 6-cyano-6-methoxy (ld)) have been determined. At 50" C, the rate constants for cyclization to the corresponding cyclopentylmethyl radicals are 1.65 X lo8, 1.45 X lo6, and 2.49 X IO8 s-', respectively. The rate accelerations for the cyclizations of 1 W relative to that of the parent radical, hex-5-en- ...