Ammonium Chloride → 2-(Bis-(2,2,2-trifluoroethoxy)phosphoryl)-6-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-4-methyl-hex-4-enoic Acid Methyl Ester

Beteiligte Stoffe

Reaktionsschritte

To a solution of [bis-(2,2,2-trifluoro-ethoxy)-phosphoryl]-acetic acid methyl ester (186 μL, 0.88 mmol) in anhydrous THF (2 mL) was added a solution of 1N NaN(TMS)2 in THF (0.88 mL, 0.88 mmol). The solution was stirred at room temperature for 30 minutes, whereupon a solution of 6-(4-bromo-3-methyl-but-2-enyl)-5-methoxy-4-methyl-7-(2-trimethylsilanyl-ethoxy)-3H-isobenzofuran-1-one (98 mg, 0.22 mmol) in THF (1 mL) was added. The reaction mixture was stirred overnight when a precipitate was observed. The reaction mixture was worked up by addition of a saturated aqueous solution of ammonium chloride and extraction of the product with EtOAc. The organic extract was dried and the product was purified by RP HPLC using a C18 column with a gradient of H2O, 0.1% TFA-acetonitrile, 0.1% TFA to provide 72 mg (48%) of the product as a colorless oil. 1H NMR (300 MHz, CDCl3) δ 0.05 (s, 9H), 1.22 (t, 3H, J=7 Hz), 1.81 (s, 3H), 2.18 (s, 3H), 2.5-2.7 (m, 2H), 3.3 (ddd, 1H, J=4, 12, 23 Hz), 3.40 (d, 2H, J=7 Hz), 3.65 (s, 3H), 3.76 (s, 3H), 4.29-5.13 (m, 6H), 5.13 (s, 2H), 5.28 (t, 1H, J=7 Hz) ppm; MS (m/z) 701.2 [M+Na]+.

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