III. Group Replacement Reactions
- Page ID
- 24079
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Since the reaction pictured in Scheme 1 depends upon R· adding to a molecule of the starting ester, one way to change the course of this reaction is to introduce a compound that will react more rapidly with R· than does the ester. Thiols meet this requirement.8,19–25 Hydrogen-atom abstraction by a carbon-centered radical from a thiol is rapid enough (kH = 1.4 x 108 M-1s-1 at 25 oC for abstraction from C6H5SH by Bu·)26 to occur in preference to radical reaction with the starting ester.