Triphenylphosphine → 2-[4-(Dimethoxy-phosphoryl)-but-2-enyl]-6-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-4-methyl-hex-4-enoic acid 2-trimethylsilanyl-ethyl Ester

Participants

Reaction Steps

A solution of 2-[4-(dimethoxy-phosphoryl)-but-2-enyl]-6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-4-methyl-hex-4-enoic acid (160 mg, 0.332 mmol) and trimethylsilylethanol (160 mg, 1.36 mmol) in THF (8.00 mL) was stirred with triphenylphosphine (345 mg, 1.33 mmol). To this solution was added diethyl azodicarboxylate (230 pt, 1.33 mmol) at 0° C. The mixture was allowed to warm to room temperature and stirred for 16 hours. Additional triphenylphosphine (180 mg, 0.692 mmol), trimethylsilylethanol (160 mg, 1.36 mmol), and diethyl azodicarboxylate (115 μL, 0.665 mmol) were added and the reaction mixture was stirred for another 1 day at room temperature. The reaction was worked up by removing the solvents in vacuo and purifying the residue by silica gel chromatography to provide 192 mg (85%) of the product as a clear oil. 1H NMR (300 MHz, CDCl3) δ 0.03 (s, 9H), 0.05 (s, 9H), 0.93-0.96 (m, 2H), 1.20-1.29 (m, 2H), 1.78 (s, 3H), 2.01-2.32 (m, 4H), 2.17 (s, 3H), 2.51 (d, 1H, J=22 Hz), 2.58 (d, 1H, J=22 Hz), 2.50-2.60 (m, 1H), 3.37 (d, 2H, J=7 Hz), 3.72 (d, 6H, J=11 Hz), 3.76 (s, 3H), 4.08 (appt t, 2H, J=8 Hz), 4.30 (appt t, 2H, J=8 Hz), 5.12 (s, 2H), 5.15-5.25 (m, 1H), 5.36-5.63 (m, 2H) ppm; 31P (121.4 MHz, CDCl3) δ 29.3 ppm; MS (m/z) 705.3 [M+Na]+.

Provenance & Evidence