2,6-Lutidine → [1-Cyano-5-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-1,3-dimethyl-pent-3-enyl]-phosphonic Acid

Participants

Reaction Steps

To a solution of {1-cyano-5-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-1,3-dimethyl-pent-3-enyl}-phosphonic acid diethyl ester (18 mg, 0.04 mmol) in DMF (0.5 mL) and DCM (0.5 mL) was added TMSBr (51 μL, 0.4 mmol) and 2,6-lutidine (46 μL, 0.4 mmol). The reaction solution was allowed stir at room temperature overnight before quenching with MeOH. The reaction mixture was dried under reduced pressure and the residue was purified by RP HPLC using a C18 column with a gradient of H2O, 0.1% TFA-acetonitrile, 0.1% TFA to provide 4.5 mg (33%) of the desired product. 1H NMR (300 MHz, CD3OD) δ 1.37 (d, 3H), 1.87 (s, 3H), 2.13 (s, 3H), 2.26 (m, 1H), 2.64 (m, 1H), 3.39 (m, 2H), 3.75 (s, 3H), 5.18 (s, 2H), 5.34 (m, 1H) ppm; 31P (121.4 MHz, CD3OD) δ 21.47 ppm; MS (m/z) 422 [M−H]−, 424 [M+H]+.

Provenance & Evidence