In a 5-l. three-necked flask fitted with a mercury-sealed mechanical stirrer, a 500-ml. dropping funnel, and an efficient reflux condenser are placed 2630 ml. (2856 g., 28 moles) of acetic anhydride and 57 g. of crushed anhydrous zinc chloride. This mixture is stirred and brought to gentle boiling. After 5–10 minutes at reflux, 680 ml. (714 g., 7 moles) of redistilled tetrahydrofurfuryl alcohol (Note 1) is added from the dropping funnel at such a rate that the mixture refluxes vigorously. This addition requires about 30 minutes. The mixture is then stirred and refluxed gently for 24 hours. After being cooled, about one-half of the liquid is decanted from the zinc chloride residue through a glass wool plug in a funnel into a 2-l. Claisen flask and then distilled under reduced pressure. The second portion is likewise distilled. The total weight of fore-run is 1740–1780 g. (Note 2). The 1,2,5-triacetoxypentane is collected at 155–165°/14 mm. The yield is 1500–1550 g. (87–90%).

Fifteen hundred grams (6.1 moles) of the ester and 1.2 l. of 1% sulfuric acid (6.9 ml. of concentrated acid in 1.2 l. of solution) are added to a 5-l. round-bottomed flask fitted with a reflux condenser. The mixture is heated strongly and agitated by tilting the ring stand back and forth until the two layers become homogeneous. This initial hydrolysis step requires 15–30 minutes. When homegenity is attained, the flask and condenser are set for steam distillation. The flask is heated by a Meker burner to maintain approximately constant volume, and the mixture is vigorously steam-distilled until 20 l. of distillate has been collected (Note 3). The residue is allowed to cool and then made basic to litmus paper by the addition of 10–20 g. of lime in small portions with vigorous agitation. The calcium sulfate is removed by suction filtration, the filtrate tested again with litmus paper to make certain that it is basic (Note 4), and the filtrate distilled under reduced pressure. This is most conveniently done by placing about one-half of the solution in a 2-l. Claisen flask, heating the flask in an oil bath at 100–110°, and distilling the water under the pressure of the water pump. The remainder of the filtrate is added, the water is removed, and the distillation is continued with an oil or mercury-vapor pump. The yield of 1,2,5-trihydroxypentane collected at 167–170°/0.5–1.0 mm. is 460–520 g. (63–71%); n²⁵D 1.4730 (Note 5).