Chemical Ligation of S-Scylated Cysteine Peptides to Form Native Peptides Via 5-, 11-, and 14-Membered Cyclic Transition States. - Katritzky, Alan R.; Tala, Srinivasa R.; Abo-Dya, Nader E.; Ibrahim, Tarek S.; El-Feky, Said A.; Gyanda, Kapil; Pandya, Keyur M. (Journal of Organic Chemistry, 2011)