Efficient Three-Step Sequence for the Deamination of α-Aminoesters. Application to the Synthesis of CysLT1 Antagonists.

Abstract A practical and efficient three-step sequence for the deamination of α-aminoesters is reported. This method is based on the NaBH4-mediated selective reduction of α-diazoesters to α-hydrazonoesters and has been successfully applied to the deamination of several representative α-aminoesters including some l -cysteine ethyl ester derivatives, key intermediates in the synthesis of a series of CysLT1 antagonists.