Reaktion #359292

Reaktionsgleichung

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

PPh3

diethyl azodicarboxylate

trimethylsilyl ethanol

→

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
   Einengenby concentrating the solution
2. 2
   workup.ADDITIONto dryness and addition of ether and hexanes
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), PPh3 (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 trimethylsilyl ethanol (142 μL, 0.996 mmol) in THF (3 mL). The resulting yellow solution was allowed to warm up to room temperature and stirred overnight. The reaction was worked up by concentrating the solution to dryness and addition of ether and hexanes. 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 clear 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).

Quelle