[摘要]:We herein describe the design and synthesis of a series of BACE-1 inhibitors incorporating a P1-substituted hydroxyl ethylene transition state isostere. The synthetic route starting from commercially available carbohydrates yielded a pivotal lactone intermediate with excellent stereochemical control which subsequently could be diversified at the PI-position. The final inhibitors were optimized using three different amines to provide the residues in the P2'-P3' position and three different acids affording the residues in the P2-P3 position. In addition we report on the stereochemical preference of the P1'-methyl substituent in the synthesized inhibitors. All inhibitors were evaluated in an in vitro BACE-I assay where the most potent inhibitor, 34-(R), exhibited a BACE-1 IC50 Value of 3.1 nM. (C) 2009 Published by Elsevier Masson SAS.