Lithium Hydroxide → 2-[(5-Carboxypentyl)oxy]-6-[6-[[3,4-dihydro-4-oxo-8-(3-phenylpropyl)-2H-1-benzopyran-7-yl]oxy]hexyl]benzenepropanoic Acid

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Reaction Steps

The 2-[6-[[3,4-dihydro-4-oxo-8-(3-phenylpropyl)-2H-1-benzopyran-7-yl]oxy]hexyl]-6-[(6-methoxy-6-oxohexyl)oxy]benzenepropanoic acid methyl ester from the preceding example (0.38 g; 0.565 mmol) was saponified by stirring with 2 mL of 3N aqueous lithium hydroxide, in 15 mL of tetrahydrofuran for 24 hr, at room temperature. Work-up as in example 4 followed by flash-chromatography on silica gel (eluting with 96:3:1 chloroform-methanol-acetic acid) and recrystallization from hexane-ethyl acetate gave 0.36 g (98%) of the title compound as a colorless solid, mp 97°-98° C.

Provenance & Evidence