Stereoselective Synthesis of Constrained Azacyclic Hydroxyethylene Isosteres as Aspartic Protease Inhibitors: Dipolar Cycloaddition and Related Methodologies toward Branched Pyrrolidine and Pyrrolidinone Carboxylic Acids
作者:Stephen Hanessian、Hongying Yun、Yihua Hou、Marina Tintelnot-Blomley
DOI:10.1021/jo050740w
日期:2005.8.1
[GRAPHICS]The synthesis of three vicinally substituted azacyclic carboxylic acids in enantiopure form was achieved from a common (x-amino aldehyde originating from (L)-leucine. Pyrrolidines and pyrrolidinones were elaborated from a,beta-unsaturated gamma-hydroxy-delta-amino acids via azomethine ylide 1,3dipolar addition and conjugate addition/cyclization strategies, respectively. The azacyclic amino acids were incorporated in a pseudopeptide now encompassing a hydroxyethylene isostere. Low nanomolar inhibition of BACE1, an enzyme implicated in the cascade of events leading to plaque formation in Alzheimer's disease, was found with a pyrrolidinone analogue.