(L)-ethyl lactate → 2-{[4-(4-Hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-2-methyl-but-2-enyloxymethyl]-phenoxy-phosphinoyloxy}-propionic Acid Ethyl Ester

Participants

Reaction Steps

To a solution of [4-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-2-methyl-but-2-enyloxymethyl]-phosphonic acid monophenyl ester (18.5 mg, 0.040 mmol) and ethyl (S)-(−)-lactate (47 μL, 0.400 mmol) in pyridine (0.5 mL) was added PyBOP (32 mg, 0.060 mmol). The solution was stirred at room temperature for 1 hour, when an additional portion of PyBOP (21 mg, 0.040 mmol) was added. The solution was stirred for another hour and concentrated. The residue was purified by HPLC to provide 7.5 mg of the desired product as a clear oil. 1H NMR (300 MHz, CD3OD) δ 1.22 and 1.25 (t, 3H, J=7 Hz), 1.42 and 1.50 (d, 3H, J=7 Hz), 1.82 and 1.83 (s, 3H), 2.16 (s, 3H), 3.47 (d, 2H, J=7 Hz), 3.78 (s, 3H), 3.89 (d, 1H, J=8 Hz), 3.93-4.02 (m, 3H), 4.10-4.22 (m, 2H), 4.94-5.08 (m, 1H), 5.25 (s, 2H), 5.50-5.60 (m, 1H), 7.15-7.27 (m, 3H), 7.33-7.41 (m, 2H) ppm; 31P (121.4 MHz, CD3OD) δ 18.9, 20.3 ppm (diastereomers at phosphorus); MS (m/z) 549.2 [M+H]+, 571.3 [M+Na]+.

Provenance & Evidence