Stereoselective Synthesis of the Optical Isomers of a New Muscarinic Receptor Antagonist,HL-031120

摘要

We present here a practical stereoselective synthetic method to produce enantiopure isomers of a new muscarinic receptor antagonist,HL-031120 (3-quinucli-dinyl-2'-cyclopentyl-2'-hydroxy-2'-phenylacetate,I).Four optical isomers were effectively by stereoselective synthesized using pivaldehyde as steric hindrance agent from the chiral starting material,(S) or (R)-mandelic acid.The isomers were obtained with 70-76% yields in 98-99% e.e.