We report an asymmetric synthesis of a potent tyrosine phosphatase inhibitor, RK-682 and its analogs. The absolute stereochemistry of RK-682 was determined to be (R). The inhibitory activities of RK-682 and its analogs,(R)-1a,(S)-1a,(R)-1b and (R)-1c toward various protein phosphatases (VHR, cdc25A, cdc25B, and PP1) are also reported.