In the past, to produce 1,5-pentanediol, a method is well known in which a carboxylic acid mixture raw material including glutaric acid, adipic acid, 6-hydroxy caproic acid, and so forth which are by-produced during manufacturing of cyclohexanone and/or cyclohexanol by air-oxidation of cyclohexane is esterified, and then they are reduced by hydrogen by using a copper-based catalyst to give 1,5-pentanediol and 1,6-hexanediol, which is then followed by separation by distillation (see, for example, Patent Document 1). As a closely-related method, a method is known in which a mixture of dicarboxylic acids which are by-produced in an adipic acid manufacturing plant is used as the raw material thereof (see, for example, Patent Document 2).
On the other hand, as a method for producing 1,5-pentanediol by using tetrahydrofurfuryl alcohol as the manufacturing raw material thereof, a method for producing 1,5-pentanediol from tetrahydrofurfuryl alcohol in the presence of a copper-chromium type catalyst and a method for producing 1,5-pentanediol from furfural in the presence of a copper-aluminum type catalyst have been reported (see, for example, Patent document 3, Patent Document 4, and Non-Patent Document 1).
Additionally, in recent years, a method for producing an alkylene polyol by using a metal catalyst other than a copper type catalyst has been reported (see, for example, Patent Document 5). In this Patent Document 5, a method is described in which 1,5-pentanediol is obtained as a mixture with ring-opened compounds such as 1,2-pentanediol and 1-pentanol as well as a decomposed product such as 2-methyltetrahydrofuran by using an aqueous solution containing tetrahydrofurfuryl alcohol as the manufacturing raw material thereof in the presence of a copper-containing catalyst supporting rhodium and one or more metal atoms selected from rhenium, molybdenum, and tungsten.    Patent Document 1: International Publication No. WO1997/031882    Patent Document 2: Japanese Patent Laid-Open Publication No. 2001-316311    Patent Document 3: U.S. Pat. No. 2,768,978    Patent Document 4: U.S. Pat. No. 627,293    Patent Document 5: Japanese Patent Laid-Open Publication No. 2009-46417    Non-Patent Document 1: Organic Synthesis Coll. Vol. 3, p. 693 (1955); Vol. 26, p. 83 (1946).
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