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A solution of 10.29 g of diethyl 2-[5-(2-methoxyethoxy)methoxypentyl]malonate (prepared as described in Preparation 61) dissolved in 100 ml of tetrahydrofuran was added dropwise to 2.40 g of lithium aluminum hydride dispersed in 100 ml of tetrahydrofuran, whilst ice-cooling (at 5° to 7° C.). The mixture was then stirred at room temperature for 3 hours, and then 9.60 ml of a 4% w/v aqueous solution of sodium hydroxide were added dropwise whilst maintaining the temperature at from 5° to 9° C. The mixture was stirred for 30 minutes at room temperature, after which it was filtered with a Celite filter aid, and the filtrate was concentrated by evaporation under reduced pressure. The residue was subjected to column chromatography through 105 g of silica gel, and 6.94 g of the title compound were obtained, as a colorless oil, from those fractions eluted with mixtures of methylene chloride and methanol ranging from 98:2 to 95:5 by volume.

1. temperaturecooling (at 5° to 7° C.)
2. temperaturewhilst maintaining the temperature at from 5° to 9° C
3. stirringThe mixture was stirred for 30 minutes at room temperature
4. filtrationafter which it was filtered with a Celite
5. filtrationfilter aid
6. concentrationthe filtrate was concentrated by evaporation under reduced pressure