Lithium Hydroxide → 2-[4-(Diethoxy-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

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Reaction Steps

A mixture of 2-[4-(diethoxy-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 methyl ester 159C (33 mg, 0.063 mmol) and lithium hydroxide (44 mg) in a mixture of THF (6 mL) and water (1 mL) was stirred at room temperature for 6 hours. The organic solvent was removed and the residue was partitioned between ethyl acetate and 5% aqueous sodium bicarbonate. The aqueous layer was acidified with 2 N HCl and extracted with ethyl acetate. The ethyl acetate extract was concentrated, affording 2-[4-(diethoxy-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 159D as an oil (30 mg, 100%); 1H NMR (300 MHz, CDCl3) δ 1.27 (m, 6H), 1.79 (s, 3H), 2.0-2.7 (m, 8H), 3.37 (d, J=6.6 Hz), 3.75 (s, 3H), 4.08 (m, 4H), 5.19 (s, 2H), 5.25 (m, 1H), 5.44 (m, 1H), 5.55 (m, 1H), 5.45 (m, 2H) ppm.

Provenance & Evidence