Trimethyl phosphite → 1-[2-(Dimethoxy-phosphoryl)-acetyl]-cyclopropanecarboxylic acid n-butyl ester

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Reaction Steps

A solution of 16 3.42 g (13.0 mmol) and trimethylphosphite (1.95 mL, 2.05 g, 16.5 mmol) in toluene (45 mL) was refluxed for 15 hours. The solvent and remaining trimethyl phosphite were then distilled off, and the residue was purified by column chromatography (2-10% isopropanol/hexane) to give 2.26 g (7.74 mmol; 59% yield) of 17. 1H NMR (500 MHz, CDCl3) δ 0.95 (3H, t, J=7.3 Hz), 1.39 (2H, m), 1.57-1.67 (6H, m), 3.75 (2H, d, JH-P=22.1 Hz), 3.78 (6H, d, JH-P=11.1 Hz), 4.15 (2H, t, J=6.7 Hz). 13C NMR (125 MHz, CDCl3) δ 13.7, 19.2, 20.6, 30.5, 35.3, 39.8, 40.8, 52.9 (d, JC-P=6.0 Hz), 170.8, 197.0 (d, JC-P=6.3 Hz). MS (EI) m/z 292 (15, M+), 264 (17), 236 (21), 218 ((45), 191 (18), 163 (22), 150 (59), 126 (100); exact mass (ESI) calculated for C12H21O6PNa ([M+Na]+) 315.0973, found 315.0963.

Provenance & Evidence