Highly efficient synthesis of medium-sized lactams via intramolecular Staudinger–aza-Wittig reaction of ω-azido pentafluorophenyl ester: synthesis and biological evaluation of LY411575 analogues

A highly efficient method for the synthesis of medium-sized lactams based on intramolecular Staudinger–aza-Wittig reaction of ω-azido pentafluorophenyl ester has been developed. A variety of 7–10 membered lactams were synthesized in excellent yields. Application of the method to the synthesis of analogues of a potent γ-secretase inhibitor LY411575 and their biological evaluation are also described.