Reaktion #61907

Reaktionsgleichung

6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-4-methyl-hex-4-enoic acid methyl ester

triphenylphosphine

diethyl azodicarboxylate

2-trimethylsilylethanol

→

desired product

Ausbeute 86.5%

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

Ausbeute 86.5%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction was concentrated to dryness and ether and hexanes
2. 2
   workup.ADDITIONwere added
3. 3
   SonstigeTriphenylphosphine oxide was removed by filtration
4. 4
   Einengenthe filtrate was concentrated
5. 5
   Sonstigepurified by silica gel chromatography

Vorschrift

To a solution of 6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-4-methyl-hex-4-enoic acid methyl ester (222 mg, 0.66 mmol), triphenylphosphine (260 mg, 0.996 mmol), and diethyl azodicarboxylate (173 mg, 0.996 mmol) in THF (3 mL) at 0° C. was added a solution of 2-trimethylsilylethanol (142 μL, 0.996 mmol) in THF (3 mL). The resulting yellow solution was allowed to warm to room temperature and stirred overnight. The reaction was concentrated to dryness and ether and hexanes were added. Triphenylphosphine oxide was removed by filtration and the filtrate was concentrated and purified by silica gel chromatography to provide 248 mg of the desired product as a colorless oil. 1H NMR (300 MHz, CDCl3) δ 0.03 (s, 9H), 1.18-1.30 (m, 2H), 1.81 (s, 3H), 2.18 (s, 3H), 2.25-2.33 (m, 2H), 2.37-2.45 (m, 2H), 3.42 (d, 2H, J=7 Hz), 3.62 (s, 3H), 3.77 (s, 3H), 4.25-4.35 (m, 2H), 5.13 (s, 2H), 5.12-5.22 (m, 1H) ppm.

Quelle