Method for producing lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate

Abstract

A process for the preparation of a product comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the use of a compound selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts as starting compounds for preparing said product compounds, and the use of a heterogeneous hydrogenation catalyst in the process for the preparation of a product comprising one or more of said product compounds are described.

Description

[Technical Field]

[0001] The present application relates to a method for producing a product comprising one or more product compounds selected from the group consisting of (a) lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy, and carboxylate, and / or (b) one or more reaction products of one or more of said compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy, and carboxylate, the use of compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts as starting compounds for producing such products (a) and (b), and the product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy, and carboxylate. The use of a heterogeneous hydrogenation catalyst in the method for producing a product comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy, and carboxylate is also described. [Background technology]

[0002] Lactones derived from tricarboxylic acids are important synthetic targets due to their wide range of applications on an industrial scale. Such lactones can replace monomers (e.g., for ring-opening polymerization) and solvents (e.g., γ-butyrolactone, γ-valerolactone), which are currently produced primarily petrochemically. Due to the finite and unstable supply of fossil raw materials and environmental reasons, it is becoming increasingly important to replace fossil raw materials with non-fossil raw materials, i.e., raw materials obtained from renewable resources.

[0003] Radial tricarboxylic acids, such as citric acid, isocitric acid, tricarballylic acid, and aconitic acid, their esters, anhydrides, and salts, can be used as precursors for lactones, provided that selective formation of the lactone is achieved. Tricarboxylic acids such as citric acid and aconitic acid can be obtained from renewable resources, for example, from plant materials by sugar fermentation.

[0004] Unfortunately, tricarboxylic acids are difficult substrates for typical reduction procedures due to the following main reasons: pKA values ​​are incompatible with many catalytic materials; The central C=O bond has low electrophilicity, - A strong tendency to decarboxylate with increasing temperature; Low solubility in most organic solvents, High reduction potential (which leads to neutralization with e.g. sodium hydride, but reduction only with stronger reducing agents such as lithium aluminum hydride).

[0005] Citric acid in particular is very susceptible to decarboxylation and dehydration as the temperature increases.

[0006] Green Chem. 2017, 19, 4642 (De Vos et al.) describes the decarboxylation and dehydration of citric acid in an aqueous system using a Ni / ZrO catalyst under reducing conditions (20 bar H2, 175 °C, 6 h) to itaconic acid as the major product (53%). The authors propose that itaconic acid then rehydrates to a β-hydroxycarboxylic acid, which ultimately cyclizes in situ to β-carboxyl-γ-butyrolactone. The so-called "isomeric hydration" products (2-(hydroxymethyl)succinic acid, β-carboxyl-γ-butyrolactone, and 2-hydroxy-2-methylsuccinic acid) account for 41% of the reaction products.

[0007] The following is also related art: U.S. Patent No. 4,218,381 (US4,218,381 A), P.-F.Xu et al. / Tetrahedron Letters 46 (2005) 3815~3818、 I.Thapa et al., Catalysis Today 319 (2019) 191~196、 G.Venkateswara Rao et al., Food Chemistry 120 (2010) 235~239、 H.Hida et al., Biosci., Biotechnol., Biochem. 69 (8), 1555~1561, 2005, R.Gerardy et al., Org. Process Res Dev. 2017, 21, 2012~2017, HGMWalravenおよびUK Pandit, Tetrahedron Vol. 36, 321~327ページ.

Prior Technical Literature

Charter Documents

[0008] [Patent Document 1] U.S. Patent No. 4218381

Non-licensed literature

[0009]

Non-patent document 1

Non-patent document 2

Non-patent document 3

Non-patent document 4

[0010] A first object of the present invention is to provide a method for producing a product comprising (a) one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, and / or (b) one or more reaction products of one or more of said compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, wherein the method can use starting materials obtained from renewable resources.

[0011] A further object is to provide a process for the selective formation of lactone groups under hydrogenation conditions from two carboxyl groups of an aliphatic tricarboxylic acid, two carboalkoxy groups of an ester of an aliphatic tricarboxylic acid, two carboxylate groups of a salt of an aliphatic tricarboxylic acid, or from an anhydride group of an anhydride of an aliphatic tricarboxylic acid, which process provides a useful yield of lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, and suppresses undesired side reactions that could result in loss of carbon atoms by decarboxylation or complete hydrogenation to a polyol (see Figure 1, which shows, for the starting compound citric acid, the formation of a lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, and the undesired complete conversion of the carboxyl groups of citric acid to hydroxy groups). [Means for solving the problem]

[0012] The first and other objects of the present invention are: (a) one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate; and / or (b) one or more reaction products of said one or more compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate. 1. A method for producing a product comprising at least the following steps: (i) providing or preparing a starting material comprising one or more starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts; (ii) providing or preparing a solvent having a dielectric constant greater than that of n-butanol; and (iii) the one or more starting compounds provided or prepared in step (i), At temperatures ranging from 80℃ to 140℃, Hydrogen partial pressure in the range of 15MPa to 30MPa, in the solvent provided or prepared in step (ii), and in the presence of a heterogeneous hydrogenation catalyst comprising one or more metals selected from the group consisting of Co, Rh, Ir, Ni, Pd and Pt, chemically converting two carboxyl groups, two carboxylate groups, two carboalkoxy groups, or anhydride groups present in said one or more starting compounds to form lactone groups under hydrogenation conditions to yield a product comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate; This can be achieved by the method comprising:

[0013] It has surprisingly been found that under the hydrogenation conditions defined above, it is possible to achieve selective formation of lactone groups from two carboxyl groups of an aliphatic tricarboxylic acid, from two carboalkoxy groups of an ester of an aliphatic tricarboxylic acid, from two carboxylate groups of a salt of an aliphatic tricarboxylic acid, or from an anhydride group of an anhydride of an aliphatic tricarboxylic acid, and that when the hydrogenation reaction parameters in step (iii) are selected as defined above and a heterogeneous hydrogenation catalyst as defined above and a solvent as defined above are used, it is possible to obtain a useful yield of a product compound selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate. Thus, when the chemical conversion of the starting compound in step (iii) is carried out using the parameters defined above, the heterogeneous hydrogenation catalyst as defined above, and the solvent as defined above, undesired side reactions are suppressed.

[0014] Without wishing to be bound by theory, it is presently believed that in step (iii) one of the carboxyl, carboxylate, carboalkoxy and anhydride groups of the starting compound is reduced under hydrogenation conditions to form a hydroxy group, which then undergoes a ring-closing reaction with one of the carboxyl, carboxylate or carboalkoxy groups, or with another of the same molecule (intramolecular esterification), to give a lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate.

[0015] When the starting compound is an aliphatic tricarboxylic acid, under the hydrogenation conditions defined above, two of its carboxyl groups selectively form lactone groups, and one carboxyl group remains. When the starting compound is a salt of an aliphatic tricarboxylic acid, under the hydrogenation conditions defined above, two of its carboxylate groups selectively form lactone groups, and one carboxylate group remains. When the starting compound is an ester of an aliphatic tricarboxylic acid, under the hydrogenation conditions defined above, two of its carboalkoxy groups selectively form lactone groups, and one carboalkoxy group remains, or is reduced to a hydroxy group under the hydrogenation conditions defined above. When the starting compound is an anhydride of an aliphatic tricarboxylic acid, under the hydrogenation conditions defined above, a lactone is selectively formed from the anhydride group, and one carboxyl group remains.

[0016] When the starting compound is an α-hydroxycarboxylic acid, its salt or its anhydride, the lactone formed in this manner has a carboxyl group and a hydroxyl group and can be dehydrated by subsequent hydrogenation to a lactone having a carboxyl group and no hydroxyl group (see FIG. 2, which shows the formation of a lactone having a carboxyl group and a hydroxyl group for the starting compound citric acid and its subsequent dehydration and hydrogenation to a lactone having a carboxyl group and no hydroxyl group).

[0017] In the case of (a) as defined above, the product resulting from step (iii) is the end product of the process, comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, wherein the end product comprises or consists of one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0018] In the case of (b) as defined above, the product resulting from step (iii) comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate is an intermediate product, and said intermediate product is converted into a final product comprising one or more reaction products of one or more of said compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate by carrying out one or more further steps subsequent to step (iii) as defined above, wherein the intermediate product comprises or consists of one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate, and the final product comprises or consists of one or more reaction products of one or more of said compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate (see below for details).

[0019] In step (i) of the method defined above, aliphatic tricarboxylic acids, Esters of aliphatic tricarboxylic acids, anhydrides of aliphatic tricarboxylic acids, Salts of aliphatic tricarboxylic acids A starting material is prepared or provided that includes one or more starting compounds selected from the group consisting of: Among these starting compounds, aliphatic tricarboxylic acids are preferred.

[0020] As understood herein, esters of aliphatic tricarboxylic acids do not include lactones.

[0021] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts.

[0022] The starting compound, or at least one of said starting compounds, aliphatic tricarboxylic acids having a total of 6 carbon atoms, esters of aliphatic tricarboxylic acids having a total of 6 carbon atoms, anhydrides of aliphatic tricarboxylic acids having a total of 6 carbon atoms, and Salts of aliphatic tricarboxylic acids having a total of 6 carbon atoms may be selected from the group consisting of:

[0023] Among these starting compounds, aliphatic tricarboxylic acids having a total of 6 carbon atoms are preferred.

[0024] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of aliphatic tricarboxylic acids having a total number of carbon atoms of 6, their esters, their anhydrides, and their salts. Preferably, all of the starting compounds are selected from the group consisting of aliphatic tricarboxylic acids having a total number of carbon atoms of 6, their esters, their anhydrides, and their salts.

[0025] In certain cases, the starting compound, or at least one of said starting compounds, Tricarballylic acid, Esters of tricarballylic acid, Tricarballylic anhydride, and Salts of tricarballylic acid is selected from the group consisting of:

[0026] Among these starting compounds, tricarballylic acid is preferred.

[0027] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of tricarballylic acid, its esters, their anhydrides, and their salts. Preferably, all of the starting compounds are selected from the group consisting of tricarballylic acid, its esters, their anhydrides, and their salts.

[0028] In certain cases, the starting compound, or at least one of said starting compounds, α,β-unsaturated aliphatic tricarboxylic acids, Esters of α,β-unsaturated aliphatic tricarboxylic acids, Anhydrides of α,β-unsaturated aliphatic tricarboxylic acids, and Salts of α,β-unsaturated aliphatic tricarboxylic acids is selected from the group consisting of:

[0029] Among these starting compounds, α,β-unsaturated aliphatic tricarboxylic acids are preferred.

[0030] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of α,β-unsaturated aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts. Preferably, all of the starting compounds are selected from the group consisting of α,β-unsaturated aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts.

[0031] Preferably, the α,β-unsaturated aliphatic tricarboxylic acid is aconitic acid, in which case the starting compound, or at least one of the starting compounds, is Aconitic acid, Esters of aconitic acid, aconitic anhydride, and Salts of aconitic acid is selected from the group consisting of:

[0032] Among these starting compounds, aconitic acid is preferred.

[0033] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of aconitic acid, its esters, its anhydrides, and its salts, and preferably all of said starting compounds are selected from the group consisting of aconitic acid, its esters, its anhydrides, and its salts.

[0034] In certain cases, the starting compound, or at least one of said starting compounds, α-functionalized aliphatic tricarboxylic acids, Esters of α-functionalized aliphatic tricarboxylic acids, anhydrides of α-functionalized aliphatic tricarboxylic acids, and Salts of α-functionalized aliphatic tricarboxylic acids is selected from the group consisting of:

[0035] Among these starting compounds, α-functionalized aliphatic tricarboxylic acids are preferred.

[0036] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of α-functionalized aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts, and preferably all of said starting compounds are selected from the group consisting of α-functionalized aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts.

[0037] Preferably, the α-functionalized aliphatic tricarboxylic acid is an α-hydroxyaliphatic carboxylic acid, in which case the starting compound, or at least one of said starting compounds, is α-hydroxyaliphatic tricarboxylic acids, Esters of α-hydroxyaliphatic tricarboxylic acids, Anhydrides of alpha-hydroxyaliphatic tricarboxylic acids, and Salts of α-hydroxyaliphatic tricarboxylic acids is selected from the group consisting of:

[0038] Among these starting compounds, α-hydroxyaliphatic tricarboxylic acids are preferred.

[0039] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of α-hydroxyaliphatic tricarboxylic acids, their esters, their anhydrides, and their salts. Preferably, all of the starting compounds are selected from the group consisting of α-hydroxyaliphatic tricarboxylic acids, their esters, their anhydrides, and their salts.

[0040] Preferred α-hydroxyaliphatic tricarboxylic acids are citric acid and isocitric acid, in which case the starting compound, or at least one of the starting compounds, is Citric acid and isocitrate, Citric acid esters and isocitric acid esters, Citric acid anhydrous and isocitric acid anhydrous, Citric acid salts and isocitric acid salts is selected from the group consisting of:

[0041] Among these starting compounds, citric acid and isocitric acid are preferred.

[0042] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of citric acid, isocitric acid, esters thereof, anhydrides thereof, and salts thereof. Preferably, all of the starting compounds are selected from the group consisting of citric acid, isocitric acid, esters thereof, anhydrides thereof, and salts thereof.

[0043] The most preferred starting compounds in the group consisting of α-hydroxyaliphatic tricarboxylic acids, their esters, their anhydrides and their salts are citric acid, triethyl citrate and isocitric acid.For example, the starting material comprises or consists of one, two or all of citric acid, triethyl citrate and isocitric acid.Preferably, all of the starting compounds are selected from the group consisting of citric acid, triethyl citrate and isocitric acid.

[0044] Specific preferred starting compounds as mentioned above are aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts having a structure according to formula (I): [ka] [In the formula, (i) R 1 =H, R 2 =H (tricarvallic acid), or (ii) R 1 =OH, R 2 =H (isocitric acid), or (iii) R 1 =H, R 2 =OH (citric acid), or (iv) R 1 , R 2 Both show double bonds (aconitic acid)].

[0045] Thus, the starting compound, or at least one of said starting compounds, citric acid, Isocitric acid, Aconitic acid, Tricarballylic acid, esters of acids selected from the group consisting of citric acid, isocitric acid, aconitic acid and tricarballylic acid, an anhydride of an acid selected from the group consisting of citric acid, isocitric acid, aconitic acid and tricarballylic acid, and Salts of acids selected from the group consisting of citric acid, isocitric acid, aconitic acid and tricarballylic acid may be selected from the group consisting of:

[0046] Among these starting compounds, citric acid, isocitric acid, aconitic acid and tricarballylic acid are preferred.

[0047] For example, the starting material comprises or consists of one or more starting compounds selected from the group consisting of citric acid, isocitric acid, aconitic acid, tricarballylic acid, esters thereof, anhydrides thereof, and salts thereof. Preferably, all of the starting compounds are selected from the group consisting of citric acid, isocitric acid, aconitic acid, tricarballylic acid, esters thereof, anhydrides thereof, and salts thereof.

[0048] A particularly preferred starting compound is citric acid. For example, the starting material comprises or consists of citric acid. Preferably, the starting material consists of citric acid.

[0049] The total concentration of starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts may be 5% by weight or more, preferably 20% by weight or more, based on the total amount of the reaction mixture at the start of step (iii).The total concentration of all starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts may be 60% by weight or less, preferably 55% by weight or less, based on the total amount of the reaction mixture at the start of step (iii).

[0050] Here, the total amount of the reaction mixture at the start of step (iii) is the sum of the amount of the starting compound and the amount of the solvent having a dielectric constant greater than that of n-butanol.

[0051] Preferably, the total concentration of starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts is 5% to 60% by weight, based on the total amount of the reaction mixture at the start of step (iii). More preferably, the total concentration of starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts is 20% to 55% by weight, based on the total amount of the reaction mixture at the start of step (iii).

[0052] The starting material, which comprises one or more starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts, preferably selected from the group consisting of citric acid and aconitic acid, is preferably prepared or isolated from plant material. Thus, the method defined above has the advantage of being able to use starting materials obtained from renewable resources.

[0053] For example, the starting material is prepared from plant material by sugar fermentation.

[0054] Another potential renewable source of starting materials, particularly citric acid, and starting compounds obtained from the chemical conversion of citric acid, are citrus fruits.

[0055] The product resulting from step (iii) of the process defined above comprises one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate. For example, the product resulting from step (iii) may comprise or consist of one or more product compounds selected from the group consisting of lactones having one carboxyl group and one hydroxy group, and lactones having one carboxyl group and no hydroxy groups.

[0056] Preferably, all of the product compounds are compounds selected from the group consisting of lactones having one carboxyl group and one hydroxyl group, and lactones having one carboxyl group and no hydroxyl group. Preferred product compounds selected from the group consisting of lactones having one carboxyl group and one hydroxyl group are tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid and tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid. Preferred product compounds selected from the group consisting of lactones having one carboxyl group and no hydroxyl group are tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid.

[0057] In certain preferred cases, the product resulting in step (iii) comprises two or more product compounds selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid, tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, tetrahydro-5-oxo-3-furanacetic acid, and tetrahydro-2-oxo-3-furanacetic acid.

[0058] Tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid has the CAS number 98136-18-6.

[0059] Tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid has not been described before and therefore does not have a CAS number.

[0060] Tetrahydro-5-oxo-3-furanacetic acid has the CAS number 5807-39-6.

[0061] Tetrahydro-2-oxo-3-furanacetic acid has the CAS number 13281-16-8.

[0062] The product compounds tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid, tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, tetrahydro-5-oxo-3-furanacetic acid, and tetrahydro-2-oxo-3-furanacetic acid can be obtained by the process according to the invention from starting compounds selected from the group consisting of citric acid (shown by way of example below), its esters, its salts, and its anhydrides: [ka]

[0063] The process according to the invention makes it possible to obtain the product compounds tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid from starting compounds selected from the group consisting of aconitic acids (shown by way of example below), their esters, their salts and their anhydrides: [ka]

[0064] The product compounds tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid can be obtained by the process according to the invention from starting compounds selected from the group consisting of tricarballylic acid, its esters, its salts and its anhydrides.

[0065] From starting compounds selected from the group consisting of isocitric acid (shown by way of example below), its esters, its salts and its anhydrides, the following product compounds can be obtained by the process according to the invention: [ka]

[0066] In the product obtained in step (iii), the total amount of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate may be 50% by mass or more, preferably 60% by mass or more, or may range from 50% to 95% by mass, based on the total amount of the remaining starting compounds and the product compounds obtained by chemical conversion of one or more starting compounds (including product compounds that are not lactones and have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate). It is understood that a certain amount of product compounds that are not lactones and have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate may result from unavoidable side reactions.

[0067] Preferably, in the product obtained in step (iii), the total amount of product compounds selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid, tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, tetrahydro-5-oxo-3-furanacetic acid, and tetrahydro-2-oxo-3-furanacetic acid is 50% by mass or more, preferably 60% by mass or more, or in the range of 50% to 95% by mass, based on the total amount of the remaining starting compounds and the product compounds obtained by chemical conversion of one or more starting compounds (including product compounds that are not lactones and have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate). It is understood that a certain amount of product compounds that are not lactones and have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate may result from unavoidable side reactions.

[0068] When an aliphatic tricarboxylic acid, or a salt thereof, or an anhydride thereof is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon atoms present in the starting compound is largely maintained, and the resulting lactone has the same number of carbon atoms as the starting compound. Thus, almost no carbon atoms of the starting compound are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight of the product (a) satisfies the above-defined conditions. Here, the total weight of the product (a) is the sum of the weights of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compound, and the product compound formed by side reactions that is not a lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0069] When an aliphatic tricarboxylic acid having 6 carbon atoms, or a salt thereof or anhydride thereof, is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon atoms present in the starting compound is mostly maintained, and the resulting lactone has 6 carbon atoms, including the carboxyl group. Therefore, almost no carbon atoms of the starting compound are lost by decarboxylation. Here, almost means that more than 50% by mass of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by mass, more preferably more than 70% by mass of the product (a) satisfies the above-defined conditions. Here, the total mass of the product (a) is the sum of the masses of the lactone having 6 carbon atoms, the remaining starting compound, and the product compounds formed by side reactions that are not lactones having 6 carbon atoms.

[0070] When an ester of an aliphatic tricarboxylic acid is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon atoms present in the aliphatic tricarboxylic acid corresponding to the ester is largely maintained, and the resulting lactone has a number of carbon atoms equal to the sum of the number of carbon atoms in the aliphatic tricarboxylic acid corresponding to the ester used as the starting compound and the number of carbon atoms in the remaining carbalkoxy groups (not involved in the formation of the lactone group) of the starting compound; or, if the carbalkoxy groups of the starting compound not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has the same number of carbon atoms as the aliphatic tricarboxylic acid corresponding to the ester used as the starting compound. Thus, almost no carbon atoms of the aliphatic tricarboxylic acid corresponding to the ester used as the starting compound are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight, of the product (a) satisfies the above-defined conditions. Here, the total mass of product (a) is the sum of the masses of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compounds, and the product compounds formed by side reactions that are not lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0071] When an ester of an aliphatic tricarboxylic acid having 6 carbon atoms is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon atoms present in the aliphatic tricarboxylic acid corresponding to the ester is largely maintained, and the resulting lactone has either 6 carbon atoms plus the number of carbon atoms in the remaining carbalkoxy groups (not involved in the formation of the lactone group) of the starting compound, or, if the carbalkoxy groups of the starting compound not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has 6 carbon atoms. Thus, almost no carbon atoms of the aliphatic tricarboxylic acid corresponding to the ester used as the starting compound are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight, of the product (a) satisfies the above-defined conditions. Here, the total mass of product (a) is the sum of the masses of lactones having 6 carbon atoms including the carboxyl group, the remaining starting compounds, and product compounds that are formed by side reactions and are not lactones and have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0072] When an aliphatic tricarboxylic acid, a salt thereof, or an anhydride thereof is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon-carbon single bonds present in the starting compound is largely maintained, and the resulting lactone has the same number of carbon-carbon single bonds as the starting compound. Therefore, the carbon-carbon single bonds of the starting compound are largely not converted to carbon-carbon double bonds by dehydration, or if carbon-carbon double bonds are formed intermediately, they are hydrogenated in situ (see FIG. 2). Here, "mostly" means that more than 50% by mass of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by mass, more preferably more than 70% by mass of the product (a) satisfies the above-defined conditions. Here, the total mass of the product (a) is the sum of the masses of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compound, and the product compound formed by side reactions that is not a lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0073] When an ester of an aliphatic tricarboxylic acid is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon-carbon single bonds present in the aliphatic tricarboxylic acid corresponding to the ester is largely maintained, and the resulting lactone has a number of carbon-carbon single bonds equal to the sum of the number of carbon-carbon single bonds in the aliphatic tricarboxylic acid corresponding to the ester used as the starting compound and the number of carbon-carbon single bonds in the remaining carboalkoxy groups (not involved in the formation of the lactone group) of the starting compound. Alternatively, if the carboalkoxy groups of the starting compound not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has the same number of carbon-carbon single bonds as the aliphatic tricarboxylic acid corresponding to the ester used as the starting compound. Thus, the carbon-carbon single bonds of the aliphatic tricarboxylic acid corresponding to the ester used as the starting compound are hardly converted to carbon-carbon double bonds by dehydration, or if carbon-carbon double bonds are formed intermediately, they are hydrogenated in situ. Here, "mostly" means that more than 50% by weight of the product (a) defined above satisfies the above-defined condition. Preferably, more than 60% by weight, more preferably more than 70% by weight, of product (a) satisfies the conditions defined above, where the total weight of product (a) is the sum of the weights of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, the remaining starting compounds and the product compounds formed by side reactions that are not lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate.

[0074] When an α,β-unsaturated aliphatic tricarboxylic acid, a salt thereof, or an anhydride thereof is used as the starting compound, it is preferably chemically converted in step (iii) to convert most of the carbon-carbon double bonds present in the starting compound into carbon-carbon single bonds, and the resulting lactone has one more carbon-carbon single bond than the starting compound. Thus, most of the carbon-carbon double bonds of the starting compound are hydrogenated in situ. Here, "mostly" means that more than 50% by mass of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by mass, more preferably more than 70% by mass of the product (a) satisfies the above-defined conditions. Here, the total mass of the product (a) is the sum of the masses of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compound, and the product compound formed by side reactions that is not a lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0075] When an ester of an α,β-unsaturated aliphatic tricarboxylic acid is used as the starting compound, it is preferably chemically converted in step (iii) so that the carbon-carbon double bonds present in the aliphatic tricarboxylic acid corresponding to the ester are mostly converted into carbon-carbon single bonds, and the resulting lactone either has one more carbon-carbon single bond than the sum of the number of carbon-carbon single bonds in the α,β-unsaturated aliphatic tricarboxylic acid corresponding to the ester used as the starting compound and the number of carbon-carbon single bonds in the remaining carboalkoxy groups (not involved in the formation of the lactone group) of the starting compound, or, when the carboalkoxy groups of the starting compound not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has one more carbon-carbon single bond than the α,β-unsaturated aliphatic tricarboxylic acid corresponding to the ester used as the starting compound. Thus, the carbon-carbon double bonds of the α,β-unsaturated aliphatic tricarboxylic acid corresponding to the ester used as the starting compound are mostly hydrogenated in situ. Here, "mostly" means that more than 50% by weight of the product (a) as defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight of the product (a) satisfies the above-defined conditions. Here, the total weight of the product (a) is the sum of the weights of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compounds, and the product compounds formed by side reactions that are not lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0076] When citric acid, a salt thereof, or an anhydride thereof is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon atoms present in citric acid is largely maintained, and the resulting lactone has the same number of carbon atoms as citric acid. Therefore, almost no carbon atoms of citric acid are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight of the product (a) satisfies the above-defined conditions. Here, the total weight of product (a) is the sum of the weights of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compound, and the product compound formed by side reactions that is not a lactone and has at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0077] When an ester of citric acid is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon atoms present in citric acid is largely maintained, and the resulting lactone has either 6 plus the number of carbon atoms in the remaining carbalkoxy groups (not involved in the formation of the lactone group) of the ester of citric acid, or, if the carbalkoxy groups of the ester of citric acid not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has the same number of carbon atoms as citric acid. Thus, almost no carbon atoms of citric acid are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight, of the product (a) satisfies the above-defined conditions. Here, the total mass of product (a) is the sum of the masses of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compounds, and the product compounds formed by side reactions that are not lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0078] When citric acid, a salt thereof, or an anhydride thereof is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon-carbon single bonds present in citric acid is largely maintained, and the resulting lactone has the same number of carbon-carbon single bonds as citric acid. Therefore, the carbon-carbon single bonds of citric acid are largely not converted to carbon-carbon double bonds by dehydration, or if carbon-carbon double bonds are formed intermediately, they are hydrogenated in situ (see FIG. 2). Here, "mostly" means that more than 50% by mass of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by mass, more preferably more than 70% by mass of the product (a) satisfies the above-defined conditions. Here, the total mass of the product (a) is the sum of the masses of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compounds, and the product compounds formed by side reactions that are not lactones and have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0079] When an ester of citric acid is used as the starting compound, it is preferably chemically converted in step (iii) so that the number of carbon-carbon single bonds present in citric acid is largely maintained, and the resulting lactone has a number of carbon-carbon single bonds corresponding to the sum of the number of carbon-carbon single bonds in citric acid and the number of carbon-carbon single bonds in the remaining carboalkoxy groups (not involved in the formation of the lactone group) of the ester of citric acid. Alternatively, if the carboalkoxy groups of the ester of citric acid not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has the same number of carbon-carbon single bonds as citric acid. Thus, the carbon-carbon single bonds of citric acid are hardly converted to carbon-carbon double bonds by dehydration, or if carbon-carbon double bonds are formed intermediately, they are hydrogenated in situ. Here, "mostly" means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight, of the product (a) satisfies the above-defined conditions. Here, the total mass of product (a) is the sum of the masses of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compounds, and the product compounds formed by side reactions that are not lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0080] In step (ii) of the method defined above, a solvent is prepared or provided having a dielectric constant greater than that of n-butanol. The solvent is therefore more polar than n-butanol. A preferred solvent is protic. Such a solvent has sufficient solubility for the starting compound defined above.

[0081] The solvent provided or prepared in step (ii) may comprise one or more components selected from the group consisting of water, methanol, ethanol, n-propanol, iso-propanol, ethylene glycol, propylene glycol and cyclic ethers in proportions that result in a dielectric constant greater than that of n-butanol. Exemplary cyclic ethers are tetrahydrofuran (THF), tetrahydropyran (THP), and dioxane.

[0082] Preferably, the solvent is Water, and aqueous mixtures containing more than 50% by weight, preferably more than 70% by weight, more preferably more than 90% by weight, of water relative to the total amount of solvents; is selected from the group consisting of:

[0083] In the aqueous mixture, one or more of methanol, ethanol, n-propanol, iso-propanol, ethylene glycol, propylene glycol, cyclic ethers can be mixed with water.

[0084] In step (iii) of the above defined process, said one or more starting compounds provided or prepared in step (i) may be chemically converted into one or more product compounds as defined above at a temperature in the range of 80°C to 125°C, preferably at a temperature in the range of 95°C to 120°C.

[0085] The chemical conversion of starting compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts in the presence of selected heterogeneous hydrogenation catalysts at hydrogen partial pressures ranging from 15 MPa to 30 MPa, depending on the reaction temperature, can yield either aliphatic polyols (not according to the invention, see Figure 1), or lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, or a mixture of both types of products. Thus, in step (iii), the reaction temperature is preferably selected to selectively prepare said lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0086] Step (iii) of the above-defined method may be carried out for a period of at least 10 hours, preferably at least 20 hours. Step (iii) of the above-defined method may be carried out for a period of at most 200 hours, preferably at most 140 hours, more preferably at most 72 hours. Preferably, step (iii) of the above-defined method is carried out for a period of at least 10 hours and at most 200 hours. More preferably, step (iii) of the above-defined method is carried out for a period of at least 20 hours and at most 140 hours, preferably at most 72 hours.

[0087] In step (iii) of the above defined method, said one or more starting compounds provided or prepared in step (i) are chemically converted into one or more product compounds as defined above in the presence of a heterogeneous hydrogenation catalyst comprising one or more metals selected from the group consisting of Co, Rh, Ir, Ni, Pd and Pt.

[0088] A preferred heterogeneous hydrogenation catalyst comprises or consists of one or more metals selected from the group consisting of Co, Rh, Ir, Ni, Pd, and Pt in a total amount of 90% by mass or more, preferably 95% by mass or more, based on the total amount of the heterogeneous hydrogenation catalyst. Preferably, the total amount of Pd and Rh is 90% by mass or more, preferably 95% by mass or more. More preferably, the amount of either Pd or Rh is 90% by mass or more, preferably 95% by mass or more, based on the total amount of the heterogeneous hydrogenation catalyst.

[0089] In either case, it is understood that the catalyst may contain minor amounts of other metals and oxides contained in the amounts of heterogeneous hydrogenation catalyst described above.

[0090] Preferably, the amount of heterogeneous hydrogenation catalyst relative to the total amount of starting compounds is in the range of 0.05% by mass to 10% by mass, preferably 0.1% by mass to 7.5% by mass.

[0091] The heterogeneous hydrogenation catalyst may be supported by a support material (also called a carrier), the mass of which is not included in the above-mentioned amount of the heterogeneous hydrogenation catalyst.

[0092] The support material of the heterogeneous hydrogenation catalyst is preferably selected to withstand the hydrothermal stress resulting from the heat, water, acid and hydrocracking conditions simultaneously present during step (iii) of the process defined above.

[0093] Preferably, the support material is selected from the group consisting of metal oxides, zeolites, and carbon-based materials, preferably Al2O3, ZrO2, TiO2, SiC, carbon black, and PTFE. Combinations of different support materials are possible, for example, PTFE-supported carbon black.

[0094] In the supported catalyst, the total amount of the heterogeneous hydrogenation catalyst is preferably in the range of 1 mass % to 15 mass %, more preferably 5 mass % to 10 mass %, based on the total mass of the heterogeneous hydrogenation catalyst and the support material.

[0095] A preferred combination of catalytic metal and support material is Pd supported on carbon black and Rh supported on Al2O3.

[0096] After step (iii), the supported heterogeneous hydrogenation catalyst can be recovered, preferably by means of filtration.

[0097] The method defined above may comprise one or more further steps carried out after step (iii) defined above.

[0098] In a further step carried out after step (iii) defined above, the solvent used in step (iii) can be removed by evaporation. Evaporation of the solvent can be carried out by any suitable method. For example, evaporation of the solvent can be carried out by freeze-drying.

[0099] In a further step carried out after step (iii) defined above, one or more of the product compounds present in the product resulting from step (iii) selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate can be chemically converted to give product (b) comprising one or more reaction products of one or more of the compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate, wherein the product resulting in step (iii) comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate is an intermediate product, and said intermediate product is chemically converted to a final product comprising one or more reaction products of one or more of the compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate.

[0100] In a further step carried out after step (iii) defined above, one or more further chemicals may be added to the one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate, present in the product resulting from step (iii), to result in a reaction mixture comprising the one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate. Thus, one or more lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate; one or more additional chemical entities that are not lactones and that have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate A reaction mixture containing:

[0101] Such reaction mixtures are configured and intended for use in preparing reaction products different from those described above, which comprise one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, resulting in step (iii) as defined above (see below for details).

[0102] In the reaction mixture, the one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate may function as reactants or as solvents.

[0103] The method as defined above may comprise one, two or all of the further steps as defined above, which are carried out after step (iii) as defined above.

[0104] As explained above, in case (a), the product of the above-defined process comprises one or more resultant compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0105] The product (a) is peptides, a protein, preferably a protein selected from the group consisting of human serum albumin and bovine serum albumin, an enzyme, preferably an enzyme selected from the group consisting of lysozyme, protease, amylase, lipase, protease, mannanase, and cellulase; a microorganism, preferably selected from the group consisting of gram-positive bacteria, gram-negative bacteria, spore-forming bacteria, fungal spores, mycelia, and yeasts; a virus selected from the group consisting of DNA, RNA and viruses, preferably bacteriophages; The composition may be selected from the group consisting of a formulation comprising one or more materials selected from the group consisting of:

[0106] Formulations comprising one or more materials selected from the group consisting of peptides, proteins, enzymes, DNA, RNA, viruses, and microorganisms are used for a variety of different applications including biocatalysis, food applications, feed applications, home care, personal care, and agriculture.

[0107] In such formulations, the resulting compound selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate can replace conventional solvents such as 1,2-propanediol, glycerol, or sorbitol, and / or can protect and stabilize materials selected from the group consisting of peptides, proteins, enzymes, DNA, RNA, viruses, and microorganisms. More specifically, the resulting compound selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate can be used as a biostatic agent to prevent the growth of microorganisms.

[0108] Product (a) may be a mixture comprising metal cations, preferably Fe, Mg, Ca, Sr, Cu, Ag and Au cations, complexed with one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, said mixture being prepared after step (iii) of chemically converting said one or more starting compounds. Such mixtures may be selected from the group consisting of refinery products, mining products and home care products.

[0109] Product (a) may be a reaction mixture for preparing a polymer, preferably by ring-opening polymerization or by alkoxylation with ethylene oxide and / or propylene oxide, said reaction mixture being prepared after step (iii) of chemically converting said one or more starting compounds.

[0110] By ring-opening polymerization, polymers from the group of polyesters can be obtained.

[0111] The product (a) may be a reaction mixture for preparing an amide or ester of one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the reaction mixture being prepared after step (iii) of chemically converting the one or more starting compounds. Preferred esters are methyl esters and ethyl esters. The esters can be used as fragrance components. Preferred amides are methyl amides and ethyl amides.

[0112] The above-mentioned reaction mixture can be obtained in a further step carried out after step (iii) of chemically converting said one or more starting compounds by adding one or more further chemical substances to said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate.

[0113] As explained above, in case (b), the product of the above defined process comprises one or more reaction products of one or more of said compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate.

[0114] Product (b) may be selected from the group consisting of products comprising one or more polymers, preferably polyalkoxylates or polyesters, at least one of said polymers being prepared from said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate in a further step carried out after step (iii) of chemically converting said one or more starting compounds.

[0115] Product (b) may be selected from the group consisting of a solution comprising, as a solvent or solvent component, one or more reaction products of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate, preferably said one or more reaction products are selected from the group of amides and esters of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate.

[0116] In a particularly preferred method according to the invention, (a) one, two, three, or all of the resulting compounds selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid, tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, tetrahydro-5-oxo-3-furanacetic acid, and tetrahydro-2-oxo-3-furanacetic acid, and / or (b) one or more reaction products of one, two, three or all of said product compounds. and a product comprising at least the following stages: (i) providing or preparing a starting material comprising one or more starting compounds selected from the group consisting of citric acid, esters thereof, anhydrides thereof, and salts thereof; (ii) providing or preparing a solvent having a dielectric constant greater than that of n-butanol, said solvent being water or a mixture of water and one selected from the group consisting of methanol and ethylene glycol; and (iii) the one or more starting compounds provided or prepared in step (i), At temperatures ranging from 80℃ to 125℃, Hydrogen partial pressure in the range of 15MPa to 30MPa, in the solvent provided or prepared in step (ii), and In the presence of a heterogeneous hydrogenation catalyst containing Pd or Rh, chemically converting under hydrogenation conditions two carboxyl groups, two carboxylate groups, two carboalkoxy groups, or anhydride groups present in said one or more starting compounds to form lactone groups to produce a product comprising one or more product compounds selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid, tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, tetrahydro-5-oxo-3-furanacetic acid, and tetrahydro-2-oxo-3-furanacetic acid; It is prepared by a method comprising:

[0117] In another particularly preferred method according to the present invention, (a) one or both of the resulting compounds selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid; and / or (b) one or more reaction products of one or both of said product compounds and a product comprising at least the following stages: (i) providing or preparing a starting material comprising one or more starting compounds selected from the group consisting of aconitic acid, esters thereof, anhydrides thereof, and salts thereof; (ii) providing or preparing a solvent having a dielectric constant greater than that of n-butanol, said solvent being water or a mixture of water and one selected from the group consisting of methanol and ethylene glycol; and (iii) the one or more starting compounds provided or prepared in step (i), At temperatures ranging from 80℃ to 125℃, Hydrogen partial pressure in the range of 15MPa to 30MPa, in the solvent provided or prepared in step (ii), and In the presence of a heterogeneous hydrogenation catalyst containing Pd or Rh, chemically converting, under hydrogenation conditions, two carboxyl groups, two carboxylate groups, two carboalkoxy groups, or anhydride groups present in said one or more starting compounds to form a lactone group to yield a product comprising one or both product compounds selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid; It is prepared by a method comprising:

[0118] In a further particularly preferred method according to the present invention, (a) one or both of the resulting compounds selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid; and / or (b) one or more reaction products of one or both of said product compounds and a product comprising at least the following stages: (i) providing or preparing a starting material comprising one or more starting compounds selected from the group consisting of tricarballylic acid, esters thereof, anhydrides thereof, and salts thereof; (ii) providing or preparing a solvent having a dielectric constant greater than that of n-butanol, said solvent being water or a mixture of water and one selected from the group consisting of methanol and ethylene glycol; and (iii) the one or more starting compounds provided or prepared in step (i), At temperatures ranging from 80℃ to 125℃, Hydrogen partial pressure in the range of 15MPa to 30MPa, in the solvent provided or prepared in step (ii), and In the presence of a heterogeneous hydrogenation catalyst containing Pd or Rh, chemically converting, under hydrogenation conditions, two carboxyl groups, two carboxylate groups, two carboalkoxy groups, or anhydride groups present in said one or more starting compounds to form a lactone group to yield a product comprising one or both product compounds selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid; It is prepared by a method comprising:

[0119] This application is A formulation comprising one or more materials selected from the group consisting of: peptides, a protein, preferably a protein selected from the group consisting of human serum albumin and bovine serum albumin, an enzyme, preferably an enzyme selected from the group consisting of lysozyme, protease, amylase, lipase, protease, mannanase, and cellulase; a microorganism, preferably selected from the group consisting of gram-positive bacteria, gram-negative bacteria, spore-forming bacteria, fungal spores, mycelia, and yeasts; a virus selected from the group consisting of DNA, RNA and viruses, preferably bacteriophages; refinery products containing complexing agents; mining products containing complexing agents, home care products containing complexing agents, a reaction mixture for converting the one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate into the corresponding polymers, preferably by ring-opening polymerization or by alkoxylation with ethylene oxide and / or propylene oxide, the reaction mixture being prepared after step (iii), and a reaction mixture for preparing an ester or amide, more preferably a methyl ester, ethyl ester, methyl amide or ethyl amide, of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, said reaction mixture being prepared after step (iii). wherein the product comprises one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0120] Preferably, the product as defined above is lactones with one carboxyl group and one hydroxyl group, and Lactones with one carboxyl group and no hydroxyl groups The lactone is selected from the group consisting of:

[0121] The lactone is preferably selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid, tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, tetrahydro-5-oxo-3-furanacetic acid, and tetrahydro-2-oxo-3-furanacetic acid.

[0122] The product defined above can be obtained by the process defined above, preferably by one of the processes defined above.

[0123] The present invention relates to the hitherto undescribed compound tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid. [ka] Also relates to.

[0124] This application is one or more product compounds selected from the group consisting of: lactones with one carboxyl group and one hydroxyl group, and lactones having one carboxyl group and no hydroxyl groups, or A mixture of such compounds The present invention also relates to the use of one or more compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts as starting materials for the production of

[0125] With regard to the specific and preferred aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts used as starting compounds for producing the above-defined product compounds, the same applies as disclosed in connection with the above-defined process. The use of citric acid and aconitic acid as starting compounds for producing the above-defined products is most preferred.

[0126] With regard to the specific and preferred product compounds, the same applies as disclosed in connection with the method defined above. The lactone having one carboxyl group and one hydroxyl group is preferably selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid and tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid. The lactone having one carboxyl group and no hydroxyl group is preferably selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid.

[0127] A product compound selected from the group consisting of: lactones with one carboxyl group and one hydroxyl group, and Lactones with one carboxyl group and no hydroxyl groups or A mixture of such compounds in an amount of 100 kg or more, more preferably 500 kg or more, and even more preferably 1000 kg or more per batch.

[0128] Most preferably, the preferred compounds as defined above selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts are used as starting compounds in the process as defined above.

[0129] The present application also relates to the use of a heterogeneous hydrogenation catalyst comprising one or more metals selected from the group consisting of Co, Rh, Ir, Ni, Pd and Pt in a total amount of 90% by weight or more, preferably 95% by weight or more, based on the total amount of the heterogeneous hydrogenation catalyst, in a method for producing a product comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate, wherein preferably the total amount of Pd and Rh is 90% by weight or more, preferably 95% by weight or more, and more preferably the amount of Pd or Rh is 90% by weight or more, preferably 95% by weight or more, and the method comprises chemically converting one or more starting compounds selected from the group consisting of aliphatic tricarboxylic acids, esters thereof, anhydrides thereof, and salts thereof, to give a product comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carbalkoxy, hydroxy and carboxylate.

[0130] When the heterogeneous hydrogenation catalyst defined above is used with an aliphatic tricarboxylic acid, its salt, or its anhydride as the starting compound, the starting compound is preferably chemically converted in step (iii) to maintain the number of carbon atoms present in the starting compound, and the resulting lactone has the same number of carbon atoms as the starting compound. Thus, almost no carbon atoms of the starting compound are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight of the product (a) satisfies the above-defined conditions. Here, the total weight of the product (a) is the sum of the weights of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compound, and the product compound formed by side reactions that is not a lactone and has at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0131] When the heterogeneous hydrogenation catalyst defined above is used with an aliphatic tricarboxylic acid having 6 carbon atoms, or a salt thereof, or anhydride thereof as the starting compound, the starting compound is preferably chemically converted in step (iii) so that the number of carbon atoms present in the starting compound is largely maintained, and the resulting lactone has 6 carbon atoms, including the carboxyl group. Thus, almost no carbon atoms of the starting compound are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight, of the product (a) satisfies the above-defined conditions. Here, the total mass of the product (a) is the sum of the masses of the lactone having 6 carbon atoms, the remaining starting compound, and the product compounds formed by side reactions that are not lactones having 6 carbon atoms.

[0132] When the heterogeneous hydrogenation catalyst defined above is used with an ester of an aliphatic tricarboxylic acid as a starting compound, the starting compound is preferably chemically converted in step (iii) to maintain the number of carbon atoms present in the aliphatic tricarboxylic acid corresponding to the ester, and the resulting lactone has a number of carbon atoms equal to the sum of the number of carbon atoms in the aliphatic tricarboxylic acid corresponding to the ester used as a starting compound and the number of carbon atoms in the remaining carbalkoxy groups (not involved in the formation of the lactone group) of the starting compound; or, if the carbalkoxy groups of the starting compound not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has the same number of carbon atoms as the aliphatic tricarboxylic acid corresponding to the ester used as a starting compound. Thus, almost no carbon atoms of the aliphatic tricarboxylic acid corresponding to the ester used as a starting compound are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight, of the product (a) satisfies the above-defined conditions. Here, the total mass of product (a) is the sum of the masses of the lactone having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, the remaining starting compounds, and the product compounds formed by side reactions that are not lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0133] When the heterogeneous hydrogenation catalyst defined above is used with an ester of an aliphatic tricarboxylic acid having 6 carbon atoms as a starting compound, the starting compound is preferably chemically converted in step (iii) to maintain the number of carbon atoms present in the aliphatic tricarboxylic acid corresponding to the ester, and the resulting lactone has either 6 carbon atoms plus the number of carbon atoms in the remaining carbalkoxy groups (not involved in the formation of the lactone group) of the starting compound, or, if the carbalkoxy groups not involved in the formation of the lactone group are reduced to hydroxy groups under the hydrogenation conditions defined above, the resulting lactone has 6 carbon atoms. Thus, almost no carbon atoms of the aliphatic tricarboxylic acid corresponding to the ester used as a starting compound are lost by decarboxylation. Here, almost means that more than 50% by weight of the product (a) defined above satisfies the above-defined conditions. Preferably, more than 60% by weight, more preferably more than 70% by weight, of the product (a) satisfies the above-defined conditions. Here, the total mass of product (a) is the sum of the masses of the lactone having 6 carbon atoms including a carboxyl group, the remaining starting compounds, and the product compounds formed by side reactions that are not lactones and have at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate.

[0134] With regard to the specific and preferred heterogeneous hydrogenation catalysts, the same applies as disclosed in connection with the process defined above. With regard to the specific and preferred aliphatic tricarboxylic acids, their esters, their anhydrides, and their salts, which are converted in the process using the catalysts defined above, the same applies as disclosed in connection with the process defined above. The use of citric acid and aconitic acid to prepare the products defined above is most preferred.

[0135] With regard to the specific and preferred product compounds, the same applies as disclosed in connection with the method defined above. The lactone having one carboxyl group and one hydroxyl group is preferably selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid and tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid. The lactone having one carboxyl group and no hydroxyl group is preferably selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid.

[0136] With regard to the specific and preferred reaction parameters (temperature, hydrogen partial pressure, duration of chemical conversion, solvent), the same applies as disclosed in connection with the process defined above. Most preferably, a heterogeneous catalyst as defined above is used in the process as defined above. [Brief explanation of the drawings]

[0137] [Figure 1] FIG. 1 shows the formation of a lactone having a carboxyl group from citric acid, as well as the undesired complete conversion of the carboxyl group of citric acid to a hydroxy group. [Figure 2] FIG. 1 shows the formation of a lactone having a carboxyl group and a hydroxyl group from citric acid by reducing the carboxyl group to a hydroxyl group, followed by a ring-closure reaction with another carboxyl group of the same molecule (intramolecular esterification) to give a lactone having one carboxyl group, and subsequent dehydration and hydrogenation to give a lactone having a carboxyl group and no hydroxyl group. [Example]

[0138] The following examples according to the present invention are intended to further explain and illustrate the present invention without limiting the scope thereof.

[0139] FIG. 1 shows the formation of a carboxylated lactone from citric acid, as well as the undesired complete conversion of the carboxyl group of citric acid to a hydroxy group.

[0140] FIG. 2 shows the formation of a lactone having a carboxyl group and a hydroxyl group from citric acid by reducing the carboxyl group to a hydroxyl group, followed by a ring-closure reaction with another carboxyl group of the same molecule (intramolecular esterification) to give a lactone having one carboxyl group, and subsequent dehydration and hydrogenation to give a lactone having a carboxyl group and no hydroxyl group.

[0141] The preparation of carboxylic lactones from citric acid dissolved in water was carried out as follows: A heterogeneous hydrogenation catalyst (catalyst type, support material type, and amount shown in Table 1) was added to a solution of citric acid monohydrate in water as a solvent (citric acid concentration and solution amount shown in Table 1) in an autoclave. The reaction vessel was closed and then flushed twice with nitrogen gas (0.5 MPa). Stirring (700 U / min) and an initial hydrogen pressure (5 MPa) were then applied. The reaction mixture was heated to the temperature shown in Table 1, and the hydrogen pressure was increased to the value shown in Table 1. Under these conditions, the reaction mixture was stirred for the time shown in Table 1, then cooled to room temperature and flushed twice with nitrogen gas (0.5 MPa). The catalyst was then filtered off, and the solvent was removed by evaporation. The resulting oil was analyzed by gas chromatography and HPLC. The experimental parameters and results for the example using citric acid are summarized in Table 1.

[0142] The preparation of carboxyl-containing lactone from aconitic acid dissolved in water was carried out as follows: A heterogeneous hydrogenation catalyst (catalyst type, support material type, and amount shown in Table 2) was added to a solution of aconitic acid in water as a solvent (aconitic acid concentration and solution amount shown in Table 2) in an autoclave. The reaction vessel was closed and then flushed twice with nitrogen gas (0.5 MPa). Stirring (UPM shown in Table 2) and initial hydrogen pressure (5 MPa) were then applied. The reaction mixture was heated to the temperature shown in Table 2, and the hydrogen pressure was increased to the value shown in Table 2. Under these conditions, the reaction mixture was stirred for the time shown in Table 2, then cooled to room temperature and flushed twice with nitrogen gas (0.5 MPa). The catalyst was then filtered off, and the solvent was removed by evaporation. The resulting oil was analyzed by gas chromatography and HPLC. The experimental parameters and results for the example using aconitic acid are summarized in Table 2.

[0143] The preparation of carboxyl-containing lactones from tricarballylic acid dissolved in water was carried out as follows: A heterogeneous hydrogenation catalyst (type of catalyst, type of support material, and amount shown in Table 3) was added to a solution of tricarballylic acid in water as a solvent (concentration of tricarballylic acid and amount of solution shown in Table 3) in an autoclave. The reaction vessel was closed and then flushed twice with nitrogen gas (0.5 MPa). Stirring (UPM shown in Table 3) and initial hydrogen pressure (5 MPa) were then applied. The reaction mixture was heated to the temperature shown in Table 3, and the hydrogen pressure was increased to the value shown in Table 3. Under these conditions, the reaction mixture was stirred for the time shown in Table 3, then cooled to room temperature and flushed twice with nitrogen gas (0.5 MPa). The catalyst was then filtered off, and the solvent was removed by evaporation. The resulting oil was analyzed by gas chromatography and HPLC. The experimental parameters and results for the example using tricarballylic acid are summarized in Table 3.

[0144] In the table, Lactones include tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid, tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, tetrahydro-5-oxo-3-furanacetic acid, and tetrahydro-2-oxo-3-furanacetic acid; C6-polyols include 3-(hydroxymethyl)pentane-1,3,5-triol, propane-1,2,3-trimethanol, and 3-(hydroxymethyl)-2-pentene-1,5-diol; · The C5-triol is 1,3,5-pentanetriol.

[0145] In each experiment, a significant proportion of lactone was obtained.

[0146] [Table 1]

[0147] [Table 2]

[0148] [Table 3]

Claims

1. (a) one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate; or (b) one or more reaction products of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate. A method for the preparation of a product comprising at least the following steps: (i) providing or preparing a starting material comprising one or more starting compounds selected from the group consisting of aliphatic tricarboxylic acids having a total of six carbon atoms, their esters, their anhydrides, and their salts; (ii) providing or preparing a solvent having a dielectric constant greater than the dielectric constant of n-butanol; and (iii) the one or more starting compounds provided or prepared in step (i), At temperatures ranging from 80°C to 140°C, - Hydrogen partial pressure in the range of 15MPa to 30MPa, in the solvent provided or prepared in step (ii), and in the presence of a heterogeneous hydrogenation catalyst comprising one or more metals selected from the group consisting of Co, Rh, Ir, Ni, Pd and Pt, chemically converting two carboxyl groups, two carboxylate groups, two carboalkoxy groups, or anhydride groups present in said one or more starting compounds to form lactone groups under hydrogenation conditions to yield a product comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate; if the starting compound is an aliphatic tricarboxylic acid, two of its carboxyl groups selectively form lactone groups and one carboxyl group remains under the hydrogenation conditions defined above, if the starting compound is a salt of an aliphatic tricarboxylic acid, then under the hydrogenation conditions defined above, two of its carboxylate groups selectively form lactone groups and one carboxylate group remains, when the starting compound is an ester of an aliphatic tricarboxylic acid, two of its carboalkoxy groups selectively form lactone groups and one carboalkoxy group remains or is reduced to a hydroxy group under the hydrogenation conditions defined above, if the starting compound is an anhydride of an aliphatic tricarboxylic acid, under the hydrogenation conditions defined above, a lactone is selectively formed from the anhydride group and one carboxyl group remains, The method comprising:

2. the heterogeneous hydrogenation catalyst comprises one or more metals selected from the group consisting of Rh and Pd, and / or if the starting compound is an aliphatic tricarboxylic acid having 6 carbon atoms, or a salt thereof or an anhydride thereof, the resulting lactone has 6 carbon atoms including the carboxyl group, and When an ester of an aliphatic tricarboxylic acid having 6 carbon atoms is used as the starting compound, the resulting lactone has a number of carbon atoms which is either 6 plus the number of carbon atoms in the remaining carboalkoxy groups not participating in the formation of the lactone group, or, when the carboalkoxy groups not participating in the formation of the lactone group are reduced to hydroxy groups, the resulting lactone has 6 carbon atoms. The method of claim 1.

3. The one or at least one of the two or more starting compounds each comprises: selected from the group consisting of α-functionalized aliphatic tricarboxylic acids, their esters, their anhydrides and their salts, preferably from the group consisting of α-hydroxyaliphatic tricarboxylic acids, their esters, their anhydrides and their salts, more preferably from the group consisting of citric acid, isocitric acid, their esters, their anhydrides and their salts, most preferably from the group consisting of citric acid, triethyl citrate and isocitric acid, or selected from the group consisting of α,β-unsaturated aliphatic tricarboxylic acids, their esters, their anhydrides and their salts, preferably from the group consisting of aconitic acid, their esters, their anhydrides and their salts, or selected from the group consisting of tricarballylic acids, their esters, their anhydrides, and their salts; The method according to claim 1 or 2.

4. The product resulting in step (iii) is lactones having one carboxyl group and one hydroxyl group, preferably selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid and tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, and lactones having one carboxyl group and no hydroxyl groups, preferably selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid; 3. The method of claim 1 or 2, comprising one or more product compounds selected from the group consisting of:

5. the solvent having a dielectric constant greater than that of n-butanol provided or prepared in step (ii) comprises one or more components selected from the group consisting of water, methanol, ethanol, n-propanol, iso-propanol, ethylene glycol, propylene glycol and cyclic ethers; The solvent is preferably Water, and Aqueous mixtures containing more than 50% by weight of water, preferably more than 70% by weight, more preferably more than 90% by weight, based on the total amount of solvent. The method of claim 1 or 2, selected from the group consisting of:

6. The temperature in step (iii) is in the range of 80°C to 125°C, preferably in the range of 95°C to 120°C, and / or is selected so that, instead of an aliphatic polyol, said lactone is selectively prepared having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate; The method according to claim 1 or 2.

7. The heterogeneous hydrogenation catalyst comprises one or more metals selected from the group consisting of Co, Rh, Ir, Ni, Pd and Pt in a total amount of 90% by mass or more, preferably 95% by mass or more, based on the total amount of the heterogeneous hydrogenation catalyst; Preferably, the heterogeneous hydrogenation catalyst is supported by a support material, preferably the support material is selected from the group consisting of metal oxides, zeolites and carbon-based materials, preferably Al. 2 O 3 , ZrO 2 , TiO 2 , SiC, carbon black and PTFE; The method according to claim 1 or 2.

8. After step (iii), the following additional steps: - removing the solvent used in step (iii) by evaporation; chemically converting one or more of the resultant compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, present in the product resulting from step (iii), to provide a product (b) comprising one or more reaction products of the one or more compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate; and adding one or more further chemicals to the one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, present in the product resulting from step (iii), to result in a reaction mixture comprising the one or more compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate; The method according to claim 1 or 2, further comprising performing one, two or all of the steps.

9. 3. The method according to claim 1 or 2, wherein the starting material comprising one or more starter compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides and their salts, preferably selected from the group consisting of citric acid and aconitic acid, is prepared or isolated from plant material, preferably prepared by sugar fermentation.

10. 30. The method of claim 29, wherein the product is: (a) one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, said product comprising: - a formulation comprising one or more materials selected from the group consisting of peptides, proteins, enzymes, microorganisms, DNA, RNA, and viruses; a reaction mixture for preparing a polymer, preferably by ring-opening polymerization or by alkoxylation with ethylene oxide and / or propylene oxide, said reaction mixture being prepared after step (iii), a mixture comprising metal cations, preferably Fe, Mg, Ca, Sr, Cu, Ag and Au cations, complexed with said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, said mixture being prepared after step (iii), preferably selected from the group consisting of refinery products, mining products and home care products; a reaction mixture for preparing an amide or ester of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, said reaction mixture being prepared after step (iii). Selected from the group consisting of: Or, the product is (b) one or more reaction products of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate, said products comprising: a product comprising one or more polymers, preferably polyalkoxylates or polyesters, at least one of said polymers being prepared in a further step carried out after step (iii) from said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate; A solution comprising, as a solvent or solvent component, one or more reaction products of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate. Selected from the group consisting of: The method according to claim 1 or 2.

11. - a formulation comprising one or more materials selected from the group consisting of peptides, proteins, enzymes, microorganisms, DNA, RNA, and viruses; - refinery products containing complexing agents; mining products containing complexing agents, - home care products containing complexing agents, a reaction mixture for converting said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate into the corresponding polymers, preferably by ring-opening polymerization or by alkoxylation with ethylene oxide and / or propylene oxide, said reaction mixture being prepared after step (iii) of the process defined in claim 1, and A reaction mixture for preparing amides or esters of said one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy and carboxylate, said reaction mixture being prepared after step (iii) of the process defined in claim 1. A product selected from the group consisting of: lactones having one carboxyl group and one hydroxyl group, preferably selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid and tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, and lactones having one carboxyl group and no hydroxy groups, preferably selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid, comprising one or more product compounds selected from the group consisting of: The product.

12. 12. A product according to claim 11, obtainable by the process defined in claim 1.

13. Tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid.

14. A product compound selected from the group consisting of: lactones having one carboxyl group and one hydroxyl group, preferably selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid and tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, and lactones having one carboxyl group and no hydroxyl groups, preferably selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid; or Mixtures of such products 3. The use of one or more compounds selected from the group consisting of aliphatic tricarboxylic acids, their esters, their anhydrides and their salts, preferably citric acid, as starting compounds in the process according to claim 1 or 2 for the preparation of Preferably, said use, wherein said product compound, or mixture of such product compounds, is produced in an amount of 100 kg or more, more preferably 500 kg or more, and even more preferably 1000 kg or more per batch.

15. Use of a heterogeneous hydrogenation catalyst comprising one or more metals selected from the group consisting of Co, Rh, Ir, Ni, Pd and Pt in a total amount of 90% by mass or more, preferably 95% by mass or more, based on the total amount of the heterogeneous hydrogenation catalyst, comprising one or more product compounds selected from the group consisting of lactones having at least one group selected from carboxyl, carboalkoxy, hydroxy, and carboxylate; Preferably, lactones having one carboxyl group and one hydroxyl group, preferably selected from the group consisting of tetrahydro-3-hydroxy-5-oxo-3-furanacetic acid and tetrahydro-3-hydroxy-2-oxo-3-furanacetic acid, and lactones having one carboxyl group and no hydroxy groups, preferably selected from the group consisting of tetrahydro-5-oxo-3-furanacetic acid and tetrahydro-2-oxo-3-furanacetic acid, 3. The use in the method according to claim 1 or 2, for producing a product comprising one or more product compounds selected from the group consisting of:

16. 16. The use according to claim 15, wherein the heterogeneous hydrogenation catalyst comprises one or more metals selected from the group consisting of Rh and Pd.