Synthesis of the Chiral Pair of a Novel Thromboxane Antagonist, 3‐[2‐(3‐Benzenesulfonylamino‐7‐oxabicyclo[2.2.1]hept‐2‐yl‐methyl)phenyl] Propionic Acid

Preparation of the enantiomeric pair of 3-[2-(3-benzenesulfonylamino-7-oxabicyclo[2.2.1]hept-2-yl-methyl)phenyl]propionic acid, a novel thromboxane antagonist is reported. They are synthesized from either enantiomers of known (1R,2R,3R,4S)-3-[2-(3-carboxy-7-oxabicyclo[2,2,1]hept-2-yl-methyl)phenyl]-propionic acid methyl ester via epimerization, modified Curtius' rearrangement and sulfonylamino formation. Other derivatives may be prepared similarly.