Diethyl Ether → 5-(1-Benzylindol-3-yl)-2,4-pentadienal

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Reaction Steps

To a solution of ethyl 5-(1-benzylindol-3yl)-2,4-pentadienoate (1.5 g, 4.5 mmol) in 100 ml of diethyl of diethyl ether and 20 ml of tetrahydrofuran, stirred at 0° C. (ice bath), was added in portions 0.34 g (9 mmol) of LAH; the resulting mixture was stirred at room temperature for 26 hours, and worked up in manner similar to Example 13 to afford, after purifications by dry column chromatography (2:1, hexane:ethyl acetate), 1.2 g of the intermediate 2,4-pentadienol. This substance was dissolved in 250 ml of dichoromethane and 6 g of activated manganese dioxide was added. The suspension was stirred at room temperature for 6 hours. Manganese dioxide was removed by filtering through Celite® and washed thoroughly with a mixture of ethyl acetate and methylene chloride. The combined filtrate and washing were concentrated on a rotary evaporator to give 1 g of the product as an orange colored oil. This substance was used without purification in Example 15. NMR spectrum shows a singlet a 5.18 ppm and a doublet (J=7.5 Hz) at 9.48 ppm.

Provenance & Evidence