N-Ethyl-5-phenylisoxazolium-3'-sulfonate (Woodward's Reagent K) as a Reagent for Nucleophilic Side Chains of Proteins

Article abstract of DOI:10.1021/ja00278a030

N-Ethyl-5-phenylisoxazolium-3'-sulfonate (1) is converted to the corresponding keto ketenimine in a hydroxide-promoted reaction with k_-OH=6.64E5 M^-1s^-1 at 25 deg C.The rate law for spontaneous hydration