Asymmetric synthesis of a 3-acyltetronic acid derivative, RK-682, and formation of its calcium salt during silica gel column chromatography

RK-682 was reported to be a potent protein tyrosine phosphatase inhibitor. We found that (R)-3-hexadecanoyl -5-hydrolxymethyltetronic acid (1) was eas ily converted to its calcium salt during column chromatography on Silica ge l 60, and this calcium salt was identical to RK-682 originally isolated fro m a natural source. Here we report details of the asymmetric synthesis of ( R)-1 and its conversion to the calcium salt. Fast atom bombardment mass spe ctrometric (FAB-MS) analysis of the free and calcium salt forms of RK-682 i s also reported.