Method of making substituted or unsubstituted gamma-lactone

Abstract

A method of forming a substituted or unsubstituted gamma-lactone includes forming a reaction mixture that includes a substituted or unsubstituted cyano(C4-C10)alkene and / or a hydrolysis reaction product thereof. The reaction mixture also includes an acid, a solid acid catalyst, or a combination thereof. The method includes allowing the reaction mixture to react to form the substituted or unsubstituted gamma-lactone.

Description

METHOD OF MAKING SUBSTITUTED OR UNSUBSTITUTED GAMMA¬LACTONECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 622,899 filed Jan. 19, 2024, and to U.S. Provisional Patent Application Serial No. 63 / 705,047 filed Oct. 9, 2024, the disclosures of which are incorporated herein in its entirety by reference.FIELD

[0002] This disclosure relates to a process for making a substituted or unsubstituted gamma-lactone from a substituted or unsubstituted cyano(C4-Cio)alkene and / or a hydrolysis reaction product thereof in the presence of an acid, a solid acid catalyst, or a combination thereof.BACKGROUND

[0003] Cyclic esters, such as lactones, are useful chemical intermediates in a variety of applications. There are conventional ways of producing lactones, such as dehydration of hydroxycarboxylic acids or Baeyer-Villiger chemistry of introducing an oxygen atom in a cyclic ketone ring.

[0004] Recent developments include the production of five-carbon lactones starting from several biomass-derived feedstocks such as furfural for example. However, such processes use dilute concentrations, involve long reaction times (e.g., 10 h or more), require temperatures of 100 °C or more, result in formation of byproducts, do not completely convert the starting material, suffer from low overall yield, or a combination thereof. In addition, these processes are typically capital intensive and cumbersome to scale-up.

[0005] Therefore, an industrial need still exists for a commercially viable, scalable process of making gamma-lactones from an alternate organic source that may be abundantly available.SUMMARY OF THE INVENTION

[0006] Various aspects of the present invention provide a method of forming a substituted or unsubstituted gamma-lactone. The method includes forming a reaction mixture that includes a substituted or unsubstituted cyano(C4-Cio)alkene and / or a hydrolysis reaction product thereof. The reaction mixture also includes an acid, a solid acid catalyst, or a combination thereof. The method also includes allowing the reaction mixture to react to form the substituted or unsubstituted gamma-lactone.

[0007] Various aspects of the present invention provide a method of forming a substituted or unsubstituted gamma-valerolactone. The method includes forming a reaction mixture including a substituted or unsubstituted 3 -pentenenitrile and / or a hydrolysis reaction product thereof. The reaction mixture also includes an acid, a solid acid catalyst, or a combination thereof. The method also includes allowing the reaction mixture to react to form the substituted or unsubstituted gamma-valerolactone.

[0008] Various aspects of the present invention provide a method of forming gamma- valerolactone. The method includes forming a reaction mixture including 3 -pentenenitrile. The reaction mixture also includes an acid, a solid acid catalyst, or a combination thereof.The method also includes heating the reaction mixture to 20 °C to 400 °C for 30 minutes to 5 h at ambient pressure to form the gamma-valerolactone with a yield of 95% to 100% and a conversion of the 3 -pentenenitrile of 95% to 100%.

[0009] Various aspects of the present invention provide method of forming gamma- valerolactone. The method includes forming a reaction mixture including 3 -pentenenitrile and an acid. The reaction mixture also includes a metallic catalyst including nickel sulfate, copper sulfate, zinc sulfate, a hydrate thereof, or a combination thereof. The method also includes heating the reaction mixture to 40 °C to 90 °C for 30 minutes to 5 hours at ambient pressure to form the gamma-valerolactone with a yield of 95% to 100% and a conversion of the 3 -pentenenitrile of 95% to 100%.

[0010] Various aspects of the present invention provide a substituted or unsubstituted cyano(C4-Cio)alkene for use in a method of forming a substituted or unsubstituted gammalactone. The method includes forming a reaction mixture that includes a substituted or unsubstituted cyano(C4-Cio)alkene and / or a hydrolysis reaction product thereof. The reaction mixture also includes an acid, a solid acid catalyst, or a combination thereof. The method also includes allowing the reaction mixture to react to form the substituted or unsubstituted gamma-lactone. In various aspects, the substituted or unsubstituted cyano(C4-Cio)alkene is2-methyl-3 -butenenitrile, 3 -pentenenitrile, 2-pentenenitrile, or a combination thereof, that is a product of hydrocyanation of butadiene.

[0011] Various aspects of the present invention provide an as-produced reaction product of 3 -pentenenitrile including gamma-valerolactone and >0 wt.% to <1 wt.% of components other than gamma-valerolactone.

[0012] Various aspects of the present method have various advantages over other methods of forming gamma-lactone. For example, various aspects of the present method utilize a high-volume intermediate of the nylon value chain (e.g., 3 -pentenenitrile) to form gamma-valerolactone. Various aspects of the present method form substituted or unsubstituted gamma-lactones with higher yield, higher percentage conversion, a lower concentration of byproducts in the product, or a combination thereof, as compared to other methods of forming gamma-lactones. Various aspects of the present method form substituted or unsubstituted gamma-lactones at a lower temperature, in a shorter duration, or a combination thereof, as compared to other methods.DETAILED DESCRIPTION OF THE INVENTION

[0013] Reference will now be made in detail to certain aspects of the disclosed subject matter. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0014] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

[0015] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” or “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to beunderstood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0016] The term “as-produced” as used herein means the effluent of a reaction zone that has not been purified to remove side products of the reaction.

[0017] In the methods described herein, the acts can be carried out in a specific order as recited herein. Alternatively, in any aspect(s) disclosed herein, specific acts may be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately or the plain meaning of the claims would require it. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0018] The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

[0019] The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. The term “substantially free of’ as used herein can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that about 0 wt% to about 5 wt% of the composition is the material, or about 0 wt% to about 1 wt%, or about 5 wt% or less, or less than, equal to, or greater than about 4.5 wt%, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt% or less, or about 0 wt%.

[0020] The term “organic group” as used herein refers to any carbon-containing functional group. Examples can include an oxygen-containing group such as an alkoxy group, aryloxy group, aralkyloxy group, oxo(carbonyl) group; a carboxyl group including a carboxylic acid, carboxylate, and a carboxylate ester; a sulfur-containing group such as an alkyl and aryl sulfide group; and other heteroatom-containing groups. Non-limiting examples of organic groups include OR, OOR, OC(O)N(R)2, CN, CF3, OCF3, R, C(O), methylenedioxy, ethylenedioxy, N(R)2, SR, SOR, SO2R, SO2N(R)2, SO3R, C(O)R, C(O)C(O)R, C(O)CH2C(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R)2, OC(O)N(R)2,C(S)N(R)2, (CH2)O-2N(R)C(0)R, (CH2)O-2N(R)N(R)2, N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)CON(R)2, N(R)SO2R, N(R)SO2N(R)2, N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(O)N(R)2, N(R)C(S)N(R)2, N(COR)COR, N(OR)R, C(=NH)N(R)2, C(O)N(OR)R, C(=NOR)R, and substituted or unsubstituted (Ci-Cioo)hydrocarbyl, wherein R can be hydrogen (in examples that include other carbon atoms) or a carbon-based moiety, and wherein the carbon-based moiety can be substituted or unsubstituted.

[0021] The term “substituted” as used herein in conjunction with a molecule or an organic group as defined herein refers to the state in which one or more hydrogen atoms contained therein are replaced by one or more non-hydrogen atoms. The term “functional group” or “substituent” as used herein refers to a group that can be or is substituted onto a molecule or onto an organic group. Examples of substituents or functional groups include, but are not limited to, a halogen (e.g., F, Cl, Br, and I); an oxygen atom in groups such as hydroxy groups, alkoxy groups, aryloxy groups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groups including carboxylic acids, carboxylates, and carboxylate esters; a sulfur atom in groups such as thiol groups, alkyl and aryl sulfide groups, sulfoxide groups, sulfone groups, sulfonyl groups, and sulfonamide groups; a nitrogen atom in groups such as amines, hydroxyamines, nitriles, nitro groups, N-oxides, hydrazides, azides, and enamines; and other heteroatoms in various other groups. Non-limiting examples of substituents that can be bonded to a substituted carbon (or other) atom include F, Cl, Br, I, OR, OC(O)N(R)2, CN, NO, NO2, ONO2, azido, CF3, OCF3, R, O (oxo), S (thiono), C(O), S(O), methylenedi oxy, ethylenedioxy, N(R)2, SR, SOR, SO2R, SO2N(R)2, SO3R, C(O)R, C(O)C(O)R, C(O)CH2C(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R)2, OC(O)N(R)2, C(S)N(R)2, (CH2)O-2N(R)C(O)R, (CH2)O-2N(R)N(R)2, N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)CON(R)2, N(R)SO2R, N(R)SO2N(R)2, N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(O)N(R)2, N(R)C(S)N(R)2, N(COR)COR, N(OR)R, C(=NH)N(R)2, C(O)N(OR)R, and C(=NOR)R, wherein R can be hydrogen or a carbon-based moiety; for example, R can be hydrogen, (Ci- Cioo)hydrocarbyl, alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl; or wherein two R groups bonded to a nitrogen atom or to adjacent nitrogen atoms can together with the nitrogen atom or atoms form a heterocyclyl.

[0022] The term “alkyl” as used herein refers to straight chain and branched alkyl groups and cycloalkyl groups having from 1 to 40 carbon atoms, 1 to about 20 carbon atoms, 1 to 12 carbons or, in some embodiments, from 1 to 8 carbon atoms. Examples of straight chain alkyl groups include those with from 1 to 8 carbon atoms such as methyl, ethyl, n- propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Examples of branched alkylgroups include, but are not limited to, isopropyl, iso-butyl, sec-butyl, t-butyl, neopentyl, isopentyl, and 2,2-dimethylpropyl groups. As used herein, the term “alkyl” encompasses n- alkyl, isoalkyl, and anteisoalkyl groups as well as other branched chain forms of alkyl. Representative substituted alkyl groups can be substituted one or more times with any of the groups listed herein, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups.

[0023] The term “hydrocarbon” or “hydrocarbyl” as used herein refers to a molecule or functional group that includes carbon and hydrogen atoms. The term can also refer to a molecule or functional group that normally includes both carbon and hydrogen atoms but wherein all the hydrogen atoms are substituted with other functional groups.

[0024] As used herein, the term “hydrocarbyl” refers to a functional group derived from a straight chain, branched, or cyclic hydrocarbon, and can be alkyl, alkenyl, alkynyl, aryl, cycloalkyl, acyl, or any combination thereof. Hydrocarbyl groups can be shown as (Ca- Cb)hydrocarbyl, wherein a and b are integers and mean having any of a to b number of carbon atoms. For example, (Ci-C4)hydrocarbyl means the hydrocarbyl group can be methyl (Ci), ethyl (C2), propyl (C3), or butyl (C4), and (Co-Cb)hydrocarbyl means in certain aspects there is no hydrocarbyl group.

[0025] As used herein, the term “polymer” refers to a molecule having at least one repeating unit and can include copolymers.Method of forming a substituted or unsubstituted gamma-lactone.

[0026] Various aspects of the present invention provide a method of forming a substituted or unsubstituted gamma-lactone. The method can include forming a reaction mixture that includes a substituted or unsubstituted cyano(C4-Cio)alkene and / or a hydrolysis reaction product thereof. The reaction mixture also includes an acid, a solid acid catalyst, or a combination thereof. The method also includes allowing the reaction mixture to react to form the substituted or unsubstituted gamma-lactone. The reaction mixture can include the substituted or unsubstituted cyano(C4-Cio)alkene, a hydrolysis product thereof, or a combination thereof. The hydrolysis product can include a product of basic hydrolysis of the substituted or unsubstituted cyano(C4-Cio)alkene.

[0027] The substituted or unsubstituted cyano(C4-Cio)alkene can be a substituted or unsubstituted cyano(C4-C5)alkene. The substituted or unsubstituted cyano(C4-Cio)alkene can be unsubstituted. The substituted or unsubstituted cyano(C4-Cio)alkene can be a monocyano(C4-Cio)alkene or a dicyano(C4-Cio)alkene. The substituted or unsubstitutedcyano(C4-Cio)alkene can be a substituted or unsubstituted cyano(C4)alkene or substituted or unsubstituted cyano(Cs)alkene. In various aspects, the (C4-Cio)alkene of the substituted or unsubstituted cyano(C4-Cio)alkene can be butene or pentene.

[0028] The substituted or unsubstituted cyano(C4-Cio)alkene can be substituted or unsubstituted dicyanobutene and the substituted or unsubstituted gamma-lactone can be substituted or unsubstituted 2-(5-oxotetrahydrofuran-2-yl)acetic acid. The substituted or unsubstituted cyano(C4-Cio)alkene can be substituted or unsubstituted 2-pentenenitrile and the substituted or unsubstituted gamma-lactone can be substituted or unsubstituted gammavalerolactone. The substituted or unsubstituted cyano(C4-Cio)alkene can be substituted or unsubstituted 3 -pentenenitrile and the substituted or unsubstituted gamma-lactone can be substituted or unsubstituted gamma-valerolactone. The substituted or unsubstituted cyano(C4-Cio)alkene can be substituted or unsubstituted 2-methyl-3 -butenenitrile and the substituted or unsubstituted gamma-lactone can be substituted or unsubstituted alpha-methyl- gamma-butyrol actone .

[0029] The substituted or unsubstituted cyano(C4-Cio)alkene can be dicyanobutene, 2-pentenenitrile, 3 -pentenenitrile, 2-methyl-3 -butenenitrile, or a mixture thereof. The substituted or unsubstituted cyano(C4-Cio)alkene can be 2-pentenenitrile, 3 -pentenenitrile, or a mixture thereof. The substituted or unsubstituted cyano(C4-Cio)alkene can be 3- pentenenitrile.

[0030] The reaction mixture can include the substituted or unsubstituted cyano(C4- Cio)alkene, wherein no hydrolysis treatment is performed prior to forming the reaction mixture that includes the substituted or unsubstituted cyano(C4-Cio)alkene. In other aspects, the reaction mixture can include the hydrolysis reaction product of the substituted or unsubstituted cyano(C4-Cio)alkene, wherein the substituted or unsubstituted cyano(C4- Cio)alkene is first hydrolyzed to release ammonia prior to adding the hydrolyzed product to the reaction mixture. The method can include performing the hydrolysis, or the hydrolysis can be performed prior to the onset of the method. The hydrolysis can be a basic hydrolysis.

[0031] In various aspects, the substituted or unsubstituted cyano(C4-Cio)alkene is unsubstituted 3 -pentenenitrile. In other aspects, the substituted or unsubstituted cyano(C4- Cio)alkene is a substituted 3 -pentenenitrile, wherein the gamma-lactone is substituted, and wherein the 3 -pentenenitrile has the structure:The gamma-lactone can have the structure:

[0032] The variables R’-R6can each be independently chosen from -H and Rs. At each occurrence, Rscan be independently chosen from halide, a substituted or unsubstituted (Ci-Cio)hydrocarbyl, and a (C2-Cio)hydrocarbyl optionally interrupted with 1, 2, or 3 groups chosen from -O-, -S-, and -NH-. For a substituted 3 -pentenenitrile and substituted gammavalerolactone, at least one of R’-R6is Rs. For example, one, two, or three of R’-R6can be Rs. The variable Rscan be halide or unsubstituted (Ci-Cio)hydrocarbyl. In some aspects, the gamma-valerolactone and the 3 -pentenenitrile are unsubstituted, wherein each of R’-R6is -H.

[0033] The reaction mixture can be an aqueous mixture and / or an alcoholic mixture. The reaction mixture can be a reaction solution. At the time of formation of the reaction mixture, the reaction mixture can be substantially free of 4-pentenenitrile; for example, less than 2 wt% of the reaction mixture can be 4-pentenenitrile, such as 0 wt% to 1.9 wt%, or less than or equal to 2 wt% and greater than or equal to 0 wt% and less than or equal to 0.01 wt%, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, or 1.9 wt%.

[0034] In various aspects, the reaction mixture includes the acid. The acid can be any suitable acid. The acid can be a mineral acid. The acid can include sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, boric acid, hydrofluoric acid, hydrobromic acid, perchloric acid, hydroiodic acid, acidic ionic liquid or a combination thereof. The acid can include sulfuric acid or phosphoric acid. The acid can form any suitable proportion of the reaction mixture, such as 10 wt% to 98 wt% of the reaction mixture, or 30 wt% to 95 wt%, or 40 wt% to 93 wt%, or less than or equal to 98 wt% and greater than or equal to 10 wt% and less than, equal to, or greater than 15 wt%, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 92, 94, 95, 96, or 97 wt%. The acid can be 70 wt% to 95 wt% of a total amount of theacid and the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof in the reaction mixture, or 50 wt% to 98 wt%, or less than or equal to 98 wt% and greater than or equal to 50 wt% and less than, equal to, or greater than 55 wt%, 60, 65, 70, 75, 80, 85, 90, 92, 94, 95, 96, or 97 wt%. The acid can be a liquid or dissolved solid in the reaction mixture.

[0035] In various aspects, the reaction mixture includes the solid acid catalyst. The solid acid catalyst is a solid in the reaction mixture. The solid acid catalyst can be any suitable solid acid catalyst, such as a zeolite (e.g., ZSM-5), an ion-exchange resin (e.g., Amberlyst), tungstated zirconia, a silicoaluminophosphate (e.g., SAPO 34), a perfluorosulfonic acid polymer (e.g., Nafion resin), a solid acid, solid phosphoric acid, sulfonated zirconia, montmorillonite, a sulfated metal oxide, a heteropolyacid, a solid superacid, a mesoporous material, an acid treated clay, a carbon based solid acidssuch as SOsH / PhSOsH functionalized carbon, an acidic metal-organic framework (MOF), an acidic carbon-organic framework (COF), or a combination thereof. The solid acid catalyst can include an ion-exchange resin, a zeolite, tungstated zirconia, or a combination thereof.Zeolites can include crystalline aluminosilicates that can have a three-dimensional network of channels and cavities that act as catalysts due to their acidic nature. Sulfated metal oxide catalysts can include sulfated zirconia (ZrCh), sulfated alumina (AI2O3), and sulfated tin oxide (SnCh) and can exhibit strong acidity. Heteropolyacids can include solid acids based on poly oxometalates, which are metal-oxygen clusters. Examples of heteropolyacids include phosphotungstic acid (H3PW12O40) and phosphomolybdic acid (H3PM012O40). Solid superacids are solid materials of exceptionally high acidity surpassing that of typical liquid acids, with examples including fluorosulfonic acid (FSO3H) and trifluoromethanesulfonic acid (CF3SO3H). Mesoporous materials, such as mesoporous aluminosilicates, can exhibit acidic properties and can act as solid acid catalysts. The solid acid catalyst can form any suitable proportion of the reaction mixture, such as 0.001 wt% to 90 wt% of the reaction mixture, or 30 wt% to 80 wt%, or less than or equal to 90 wt% and greater than or equal to 0.001 wt% and less than, equal to, or greater than 0.005 wt%, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 89 wt%. The solid acid catalyst can be 0.001 wt% to 95 wt% of a total amount of the solid acid catalyst and the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof in the reaction mixture, or 60 wt% to 90 wt%, or less than or equal to 95 wt% and greater than or equal to 0.001 wt% and less than, equal to, or greater than 0.005 wt%, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, or 94 wt%.

[0036] The substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof can form any suitable proportion of the reaction mixture, such as 0.01 wt% to 50 wt% of the reaction mixture, or 1 wt% to 20 wt%, or less than or equal to 50 wt% and greater than or equal to 0.01 wt% and less than, equal to, or greater than 0.05 wt%, 0.1, 0.5, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, or 45 wt%.

[0037] In various aspects, the reaction mixture can be free of added solvents. In other aspects, the reaction mixture includes one or more added solvents. The solvent can be any suitable solvent, such as water, an organic solvent, an alcohol, a non-halogenated solvent, a polar solvent, an oxygenated solvent, or a combination thereof. The solvent can be commercially and readily available. The solvent can have a normal boiling point not more than 200 °C, 190 °C, 180 °C, or not more than 175 °C, such as for ease of separation, recovery, purification from the reaction effluent, recycle for re-use in the method, or a combination thereof. The solvent can be water. The solvent can form any suitable proportion of the reaction mixture, such as 0.001 wt% to 90 wt% of the reaction mixture, or 30 wt% to 60 wt%, or less than or equal to 90 wt% and greater than or equal to 0.001 wt% and less than, equal to, or greater than 0.005 wt%, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 89 wt%.

[0038] The formation of the reaction mixture can be performed at any suitable temperature, such as a temperature of -20 °C to 400 °C, or -10 °C to 30 °C, or less than or equal to 400 °C and greater than or equal to -20 °C and less than, equal to, or greater than -15 °C, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 150, 200, 250, 300, or 350 °C. The method can include forming the reaction mixture at about room temperature (e.g., 20 °C to 30 °C). In various aspects, the method includes forming the reaction mixture and maintaining the reaction mixture during the formation thereof at a temperature of about 0 °C, or in a range of -10 °C to about 10 °C, or less than or equal to 10 °C and greater than or equal to -10 °C and less than, equal to, or greater than -9 °C, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 °C. The forming of the reaction mixture can include cooling the reaction mixture to maintain or decrease a temperature thereof.

[0039] Allowing the reaction mixture to react can include heating the reaction mixture to a reaction temperature for a heating duration. For example, the heating can include heating to a reaction temperature of 20 °C to 400 °C, 20 °C to 150 °C, or 40 °C to 90 °C, or less than or equal to 400 °C and greater than or equal to 20 °C and less than, equal to, or greater than 25 °C, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110,115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, 250, 300, or 350 °C. The reaction temperature can be maintained for a heating duration of 10 minutes to 240 h, or 10 minutes to 24 h, or 30 minutes to 5 h, or less than or equal to 24 h and greater than or equal to 30 minutes and less than, equal to, or greater than 1 h, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, or 230 h. The reaction of the reaction mixture can be performed at about ambient pressure.

[0040] The method can form the substituted or unsubstituted gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene at any suitable yield, such as a yield of 50% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 50% and less than, equal to, or greater than 55%, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%. The method can include a percent conversion of the substituted or unsubstituted cyano(C4-Cio)alkene of 80% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 80% and less than, equal to, or greater than 82%, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%.

[0041] The method can further include neutralizing remaining acid in the substituted or unsubstituted gamma-lactone, or removing solid acid catalyst form the substituted or unsubstituted gamma-lactone. The method can include extracting the substituted or unsubstituted gamma-lactone into a suitable organic solvent, such as ethyl acetate, dichloromethane, or a combination thereof. During the extraction, nitrogen-containing products of the reaction such as ammonium salts (e.g., ammonium sulfate) can be removed.

[0042] The substituted or unsubstituted gamma-lactone formed by the method can be substantially free of byproducts. For example, byproducts can be 0 wt% to 10 wt% of the produced substituted or unsubstituted gamma-lactone, or 0 wt% to 2 wt%, or less than or equal to 10 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.001 wt%, 0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 3, 4, 5, 6, 7, 8, or 9 wt%.

[0043] In various aspects, the reaction mixture is free of a metallic catalyst, or is free of dissolved catalysts. In other aspects, the reaction mixture includes a metallic catalyst that is dissolved in the reaction mixture. The method can include dissolving the metallic catalyst in the reaction mixture. The metallic catalyst can include any suitable metal, such as nickel, zinc, copper, or a combination thereof. The metallic catalyst can include a metal sulfate catalyst, such as nickel sulfate, zinc sulfate, copper sulfate, a hydrate thereof, or a combination thereof. The metallic catalyst can include copper sulfate or a hydrate thereof.The metallic catalyst can be any suitable proportion of the reaction mixture, such as 0.1 wt% to 20 wt% of the reaction mixture, or 1 wt% to 15 wt%, or less than or equal to 20 wt% and greater than or equal to 0.1 wt% and less than, equal to, or greater than 0.5 wt%, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 wt%.

[0044] The method can include heating the reaction mixture including the metallic catalyst to a reaction temperature of 20 °C to 400 °C, 20 °C to 150 °C, 20 °C to 100 °C, 40 °C to 90 °C, 150°C to 310 °C, or 175 °C to 290°C, or less than or equal to 400 °C and greater than or equal to 20 °C and less than, equal to, or greater than 25 °C, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, 250, 300, or 350 °C for a heating duration of 10 minutes to 240 h, or 10 minutes to 24 h, or 30 minutes to 5 h, or less than or equal to 24 h and greater than or equal to 30 minutes and less than, equal to, or greater than 1 h, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, or 230 h. The method can include forming the substituted or unsubstituted gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene and the metallic catalyst at a yield of 80% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 80% and less than, equal to, or greater than 82%, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%. The method can include forming the substituted or unsubstituted gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene and the metallic catalyst at a percent conversion of the substituted or unsubstituted cyano(C4-Cio)alkene of 80% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 80% and less than, equal to, or greater than 82%, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%. The formed substituted or unsubstituted gamma-lactone can be substantially free of byproducts; for example, byproducts can be 0 wt% to 10 wt% of the produced substituted or unsubstituted gamma-lactone, or 0 wt% to 2 wt%, or less than or equal to 10 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.001 wt%, 0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 3, 4, 5, 6, 7, 8, or 9 wt%.

[0045] The method can include allowing the reaction mixture to react to form the substituted or unsubstituted gamma-lactone in any suitable type of reactor. For example, the reactor can be a batch reactor. In various aspects, the reactor is a continuous reactor. For example, the reactor can be a moving bed reactor or a fluidized bed reactor. Various reaction bed types can be suitable including packed bed reactors.

[0046] The reaction can include an inert gas sparging, for example, nitrogen, helium, argon, CO2, and the like. In another embodiment, steam sparge can be used. The sparging gas is suitably chemically inert to the reaction ingredients and compatible with the equipment metallurgy. In various aspects, no gas sparging is used.

[0047] It can be desirable to remove ammonia from contact with the acid catalyst. In an embodiment, a sparging gas that is at least partially reactive with ammonia can be used. For example, a sparging gas can be steam or carbon monoxide.

[0048] In an embodiment, a sparging gas can include an acid component, for example, a Lewis acid component (e.g., CO2, BF3, or SO3).

[0049] In various aspects, the method can be of great industrial importance. The method can make use of an organic (nitrile) molecule feedstock that is commercially produced in high yields and purity from a large-scale 1,3-butadiene hydrocyanation process. The butadiene double hydrocyanation to dinitrile is a critical chemical route toward making one of the required nylon monomers, specifically Ce diamine or HMD. The hydrocyanation process is a matured and well-optimized process in the world of nylon intermediates manufacture. Therefore, the scale and availability of the unsaturated nitrile favors the viability and industrial utility of the disclosed process. The unsaturated nitrile feedstock, such as 2PN, 3PN, 2-methyl-3 -butenenitrile, or di cyanobutene, will always be available in abundance.

[0050] In various aspects, the reaction mixture can advantageously be free of chemical components such as furfural, levulinic acid, or its alkyl esters (e.g., methyl, ethyl, or iso-propyl esters of levulinic acid), furfuryl alcohol, 4-hydroxyvaleric acid, or a combination thereof, which can have a concentration in the reaction mixture of 0 wt%, 0 wt% to 0.1 wt%, 0 wt% to 0.001 wt%, < 1 wt.%, < 0.5 wt.%, < 0.1 wt.%, < 100 ppmw, or < 50 ppmw.

[0051] In various aspects, the reacted reaction mixture including the substituted or unsubstituted gamma-lactone can have an advantageously low concentration of certain chemical components that for certain end-uses are considered impurities or undesired side products. In various aspects, the reacted reaction mixture can have a very low (trace level) or zero concentration of certain chemical components, such as alpha-angelica lactone, furfuralpropyl ether, 2-methyl-tetrahydrofuran, 2-butanol, 2-pentanol, 1,4-pentanediol, heavy acid, furfuryl alcohol resin, 4-cyclopentene-l, 3-dione, propylmalonic acid, pentyl-cyclopropane, 2- cyclopenten-l-one, 5-methyl-2(3H)-furanone, 2-hexyl cyclopentanone, tetrahydro furfuryl alcohol, trans-2-undecen-l-ol, pentanoic acid, furfural, levulinic acid or its alkyl (e.g., methyl, ethyl, or iso-propyl) esters, furfuryl alcohol, 4-hydroxyvaleric acid, or a combinationthereof. In various embodiments, one or more of these chemical components can be present in the reacted reaction mixture at concentrations selected from 0 wt%, 0 wt% to 0.1 wt%, 0 wt% to 0.001 wt%, < 1 wt.%, < 0.25 wt.%, < 0.1 wt.%, < 500 ppmw < 100 ppmw, < 50 ppmw, < 30 ppmw, < 10 ppmw, < 50 ppmw, < 1 ppmw, < 0.5 ppmw, and < 0.1 ppmw. In some embodiments, the concentration of one or more of the chemical components listed in this paragraph can be undetectable using currently available analytical techniques. The wt% is based on the total reaction mixture. One ppmw is one parts per million by weight.

[0052] Further, the cost-effective chemical transformation (or lactonization) of the unsaturated nitrile to a cyclic lactone provides utilization of the unsaturated nitrile in nonnylon applications. The gamma-lactone of the present process can be useful as a biodegradable solvent in semiconductor / electronic parts cleaning, paints and dyes, petrochemical extractions, and the like. Conventionally employed solvents in these industries, such as N- methyl-2-pyrrolidone (NMP), N,N’ -dimethylpropyleneurea (DMPU), dimethylacetamide (DMAc), dimethylformamide (DMF), dimethylsulfoxide (DMSO), and acetone, are environmentally unfriendly solvents. The gamma-lactone of the present process can be a viable substitute as a drop-in-replacement for these solvents.Substituted or unsubstituted cyano(C4-Cio)alkene for use in a method of forming a gammalactone.

[0053] Various aspects of the present invention provide a substituted or unsubstituted cyano(C4-Cio)alkene for use in the method described herein for forming a substituted or unsubstituted gamma-lactone from a substituted or unsubstituted cyano(C4-Cio)alkene. The method can include any suitable embodiment of the method described herein. For example, the method can include forming a reaction mixture that includes the substituted or unsubstituted cyano(C4-Cio)alkene and / or a hydrolysis reaction product thereof, and that also includes an acid, a solid acid catalyst, or a combination thereof. The method can also include allowing the reaction mixture to react to form the substituted or unsubstituted gammalactone. In various aspects, the substituted or unsubstituted cyano(C4-Cio)alkene can be 2- methyl-3 -butenenitrile, 3 -pentenenitrile, 2-pentenenitrile, or a combination thereof. In various aspects, the 2-methyl-3-butenenitrile, 3 -pentenenitrile, or 2-pentenenitrile can be a product of hydrocyanation of butadiene.Examples

[0054] Various aspects of the present invention can be better understood by reference to the following Examples which are offered by way of illustration. The present invention is not limited to the Examples given herein.Material Names and Abbreviations used in the disclosure:

[0055] GVL gamma-valerolactone;

[0056] LA levulinic acid;

[0057] 2PN 2-pentenenitrile;

[0058] 2M3BN 2-methyl-3 -butenenitrile;

[0059] 3PN 3 -pentenenitrile;

[0060] 4PN 4-pentenenitrile;Materials.

[0061] A non-terminal unsaturated nitrile feed of 3 -pentenenitrile (3PN) was obtained as a co-product from an industrial process of 1,3 -butadiene hydrocyanation. The 3PN used in the Examples was of >95% purity and contained minor amounts of impurities, namely, 2- methyl-2 -butenenitrile, 2-methyl-3 -butenenitrile, 2-pentenenitrile, 4-pentenenitrile, valeronitrile, 4-vinyl-l -cyclohexene, and 1,5-cyclooctadiene. These impurities are typically formed during the 1,3-butadiene hydrocyanation process.

[0062] Suitable solid acid catalysts include commercially available Amberlyst type resins (amberlyst 15, amberlyst 36, amberlyst 70), Purolite USC11706H, SAPO 34 (mixed metal oxide type), solid phosphoric acid type catalysts, tungstated zirconia, ZSM type catalysts (10 to 100 Si / Al content), or ultrastable Y type zeolite.

[0063] Suitable mineral acid catalysts may include sulfuric acid, phosphoric acid, and the like. The strength of sulfuric acid used in the examples is 98 wt.%. The strength of phosphoric acid used in the examples is 85 wt.%.Example 1. Uncatalyzed formation of GVL from 3PN.

[0064] 3 -Pentenenitrile (0.81 g, 10 mmol) was added dropwise to 10 mL of 98% sulfuric acid which was cooled over ice. The mixture was allowed to warm to room temperature and placed in a heat block at 80 °C and maintained at that temperature for 5 hours. The mixture was quenched over ice and neutralized with base. The reaction mixturewas extracted with methylene chloride and gas chromatography (GC) was run on the organic and aqueous phases.

[0065] In the organic phase, the GC trace showed no gamma-valerolactone, but included byproduct materials; the 3 -pentenenitrile was fully consumed. In the aqueous phase, the GC trace showed mostly gamma-valerolactone with trace amounts of byproduct materials. The yield of the GVL was approximately 50-60%.Example 2, Formation of GVL from 3PN in the presence of catalyst.

[0066] 3 -Pentenenitrile (0.81 g, 10 mmol) was added dropwise to a mixture of 5 g of98% sulfuric acid having 0.25 g of copper sulfate pentahydrate dissolved therein which was cooled over ice. After the addition, the mixture was allowed to warm to room temperature and stirred for an hour at room temperature. The mixture was quenched over ice and neutralized with base. The reaction mixture was extracted with methylene chloride and GC was run on the organic and aqueous phases.

[0067] In the organic and aqueous phases, the GC trace showed gamma-valerolactone as the only observable product. The 3 -pentenenitrile was fully consumed (100% conversion) and the yield of GVL was 98%.Examples 3-13, Formation of GVL from 3PN in the presence of various solid acid catalysts.

[0068] In a 15 mL glass vial, about 2 g of a solid acid catalyst, about 0.42 g 3-PN, and about 0.5 g of DI water were charged. The vial was sealed and placed in a heater block maintained at 105 °C for 20 hours. After cooling the vial, about 5 mL di chloromethane was added in the vial and sonicated for 10 minutes. The resulting liquid mixture was then analyzed using gas chromatography. Table 1 provides a summary of the results obtained for various solid acid catalysts at the conditions tested.

[0069] Except the solid phosphoric acid catalyst used in Example 11, all catalysts in Table 1 were commercially available. The solid phosphoric acid catalyst used in Example 11 was prepared according to the published reference, J. Am. Chem. Soc. 1998, 120, 8502-8511, titled “Solid Phosphoric Acid Catalyst: A Multinuclear NMR and Theoretical Study”, coauthored by Haw et al. The catalyst sample, used in Example 11, was prepared from viscous paste consisting of 5.0 g of silica and about 30 g of 85% phosphoric acid (Si:P mol ratio of 1.0:3.0). This mixture was heated to 300 °C for 48h. The catalyst was washed with cold water to remove excess phosphoric acid and any oligomerized phosphoric acids.

[0070] Table 1. Examples 3-13,Example 14. Formation of GVL from 3PN in the presence of catalyst.

[0071] In a round bottom flask was taken DI water (15 mL, 0.83 mol) and cooled to 0 °C. Then, 98 wt.% sulfuric acid (15 mL, 0.27 mol), 3-pentenenitrile (5 mL, 4.19 g, 0.052 mol), and CuSO SEbO (2.5 g, 0.010 mol) were added slowly. The mixture was heated at 80 °C for 3 hours with stirring. After cooling, additional DI water was added (50 mL) and the mixture was extracted with ethyl acetate (25 mL x 4). The combined organic extract was dried over anhydrous sodium sulfate and the solvent was evaporated in a rotary evaporator. The product mixture was obtained as light-yellow colored liquid in about 79% yield from the starting material. GC analysis showed about 99% gamma-valerolactone.Example 15, Formation of GVL from 3PN in the presence of CuSOrSEEO catalyst.

[0072] Example 14 was repeated except a smaller amount of CuSO SEEO was used. The reaction mixture was 98 wt.% sulfuric acid (2.5 mL, 0.045 mol), DI water (2.5 mL, 0.14 mol), 3-pentenenitrile (0.5 mL, 0.42 g, 0.0052 mol) and Q1SO4 5H2O (50 mg, 0.00020 mol). The mixture was heated at 80 °C for 3 hours with stirring. GC analysis of the reaction mixture showed complete conversion of 3-pentenenitrile with major product as gammavalerolactone.Example 16. Formation of GVL from 3PN in the presence of CuSOrSEbO catalyst.

[0073] Example 15 was repeated except the reaction temperature was maintained at about 25 °C. The reaction mixture was 98 wt.% sulfuric acid (2.5 mL, 0.045 mol), DI water (2.5 mL, 0.14 mol), 3-pentenenitrile (0.5 mL, 0.42 g, 0.0052 mol), and CuSO SEbO (100 mg, 0.00040 mol). The reaction mixture was stirred at 25 °C for 24 hours. A very small amount of gamma-valerolactone was observed by GC.Example 17, Formation of GVL from 3PN in the presence of phosphoric acid.

[0074] In a round bottom flask were taken 85% phosphoric acid (25 mL, 0.37 mol) and 3 -pentenenitrile (5 mL, 4.19 g, 0.052 mol). The mixture was heated at 100 °C for 2 hours with stirring. After cooling, DI water was added (50 mL) and the mixture was extracted with dichloromethane (25 mL x 4). The combined organic extract was dried over anhydrous sodium sulfate and the solvent was evaporated in a rotary evaporator. The product mixture was obtained as light-yellow colored liquid in about 75% yield from the starting material.The GC analysis showed about 99% gamma-valerolactone.Example 18, Formation of GVL from 3PN in the presence of phosphoric acid.

[0075] Example 17 was repeated except the reaction mixture was extracted with methyl tert-butyl ether (50 mL x 4). The combined organic extract was dried over anhydrous sodium sulfate and the solvent was evaporated in a rotary evaporator. The product mixture was obtained as light-yellow colored liquid in about 75% yield from the starting material. The GC analysis showed about 99% gamma-valerolactone.Example 19, Formation of lactone from 2-methyl-3 -butenenitrile (2M3BN).

[0076] A chemical intermediate, 2M3BN is converted to its corresponding lactone by employing a procedure similar to any of the above Examples. The intermediate 2M3BN is commercially available from INVISTA under the tradename DYTEK® 2M3BN nitrile. The resulting lactone product, alpha-methyl-gamma-butyrolactone, is obtained in good yield.Example 20, Formation of lactone from dicyanobutene.

[0077] A chemical intermediate, dicyanobutene is converted to its corresponding lactone by employing a procedure similar to any of the above Examples. This intermediate is commercially available. The resulting product, 2-(5-oxotetrahydrofuran-2-yl)acetic acid, is obtained in good yield.Example 21, Formation of lactones from a mixture containing 2-PN and 3-PN.

[0078] The isomerization between 2PN and 3PN may result in an equilibrated mixture of 2PN and 3PN. A mixture containing unsaturated mononitriles, mainly, 2PN and 3PN, is converted to their corresponding lactone by employing a procedure similar to any of the above Examples. The resulting product, gamma-valerolactone, is obtained in good yield.Example 22, Formation of lactones at high temp of 325 °C.

[0079] In a stainless-steel reactor, a slurry of about 2 g of SAPO-34 catalyst (a micropore zeolite), about 1 g of 3-PN, and about 3 g of DI water were charged. The reactor was sealed and placed in a heater block maintained at 325 °C for 4 hours. After cooling the reactor, the resulting liquid mixture was then analyzed using gas chromatography. The desired lactone product, gamma-valerolactone, was mainly observed and the 3PN conversion was <50%.Example 23, Formation of lactones in continuous fixed-bed reactor.

[0080] A fixed-bed continuous flow reactor set-up was used in this example. The fixed-bed reactor includes a 1.9 cm (0.75-inch) internal diameter stainless steel tube approximately 38 cm (15-inches) long. The reaction zone was filled with 0.7-1.2 mm size catalyst pellets.

[0081] Liquid 3 -pentenenitrile (3PN) and water feeds were pumped separately at desired flow rates, mixed together, and the combined feed was passed through a feed preheater. The feed preheater included a heated line to vaporize the feed and was set at 225 °C to achieve heating in the temperature range of 175-250 °C. The combined 3PN-water liquid feed was completely vaporized and passed through the fixed-bed reactor in continuous mode.

[0082] The temperature of the reactor was varied in the temperature range of 175-350 °C. The fixed-bed reactor system was continuously sparged with about 10 cc / min nitrogen flow. The process was run under a back-pressure of about 2 atm. (15 psig). The reactor effluent was collected during every 60 min and analyzed by gas chromatography (GC).

[0083] In this example, the reactor was filled with the solid phosphoric acid catalyst pellets. The liquid 3PN and water feeds were pumped to the reaction system at about 10 mL / hr and about 5 mL / hr, respectively. The combined feed to the reactor was about 15 mL / hr. The temperature of the reactor was set at about 290 °C. The GC traces of the reactor effluent showed unreacted 3PN, pentenoic acids (PAs), gamma-valerolactone (GVL) and other minor by-products. The calculated yield of GVL was about >80% during the early hours of operation and the yield was stabilized at >20% after 8h of operation. The fixed-bed operation was run continuously for about 120 hours without any further decrease of GVL yield.Example 24, Formation of Lactones in continuous fixed-bed reactor.

[0084] The fixed-bed continuous reactor system, as described in Example 23, was used except the reactor was filled with the ZSM catalyst (25 : 1 Si / Al ratio) pellets. The liquid 3PN and water feeds were pumped to the reaction system at about 10 mL / hr and about 5 mL / hr, respectively. The combined feed to the reactor was about 15 mL / hr. The temperature of the reactor was set at about 290 °C. The GC traces of the reactor effluent showed unreacted 3PN, pentenoic acids (PAs), gamma-valerolactone (GVL) and other minor byproducts. The calculated yield of GVL was about >10%. Higher levels of 3PN isomers were observed in the reactor effluent samples for this example compared to Example 23.Example 25, Formation of Lactones at low temperature in continuous fixed-bed reactor.

[0085] The fixed-bed continuous reactor system, as described in Example 23, was used except the temperature of the reactor was set at about 175 °C. The GC traces of the reactor effluent showed unreacted 3PN, pentenoic acids (PAs), gamma-valerolactone (GVL) and other minor by-products. The calculated yield of GVL was about >80% during the early hours of operation. The yield continued to drop below 10% during its 50h of continuous operation.Example 26, Recovery of catalyst activity in continuous fixed-bed reactor.

[0086] The reaction temperature of the experiment from Example 25 was increased to 225 °C after 50h. The GC traces of the reactor effluent showed unreacted 3PN, pentenoic acids (PAs), gamma-valerolactone (GVL) and other minor by-products. The calculated yield of GVL recovered and was observed to be about >10% as the run continued.Example 27, Product analysis

[0087] The reaction product of solid acid-catalyzed synthesis of gamma-valerolactone (GVL) starting from 3PN was extracted using an organic solvent, for example, methyl-tert- butyl-ether (MTBE). The extractant phase containing the GVL and other by-products product was analyzed using gas chromatography (GC) FID detection technique. The GC peak area % method was used for the major GC peaks.

[0088] The MTBE-extracted GVL product was analyzed to contain about 94 % GVL, 3.5% pentenoic acids, 0.5-1% pentenenitriles, <0.5% cyclopentanone, and <0.1-0.5% other minor impurities. Purification of the MTBE-extracted GVL product can yield >99.0%, forexample, >99.25% or >99.5% or >99.75% or >99.8% or >99.9% or >99.95% purity GVL product.

[0089] The product GVL, prepared according to the present method, can have an advantageously low concentration of certain chemical components that for certain end-uses are considered impurities or undesired side products. The product can have a very low (trace level) or zero concentration of certain chemical components, such as alpha-angelica lactone, furfural -propyl ether, 2-methyl -tetrahydrofuran, 2-butanol, 2-pentanol, 1,4-pentanediol, heavy acid, furfuryl alcohol resin, furfural, 4-cyclopentene-l,3-dione, propylmalonic acid, pentyl-cyclopropane, 2-cyclopenten-l-one, 5-methyl-2(3H)-furanone, 2-hexyl cyclopentanone, tetrahydro furfuryl alcohol, trans-2-undecen-l-ol, pentanoic acid, levulinic acid or its alkyl (e.g., methyl, ethyl, or iso-propyl) esters, furfuryl alcohol, 4-hydroxyvaleric acid, or a combination thereof. Any one or more of these chemical components can be present in the reaction product at concentrations selected from 0 wt%, 0 wt% to 0.1 wt%, 0 wt% to 0.001 wt%, < 1 wt.%, < 0.25 wt.%, < 0.1 wt.%, < 500 ppmw, < 100 ppmw, < 50 ppmw, < 30 ppmw, < 10 ppmw, < 50 ppmw, < 1 ppmw, < 0.5 ppmw, and < 0.1 ppmw of the total composition. In some embodiments, the concentration of one or more of the chemical components listed in this paragraph can be undetectable using currently available analytical techniques.

[0090] The product GVL, prepared according to the present method, can have an advantageously long shelf life resulting from low concentrations of certain chemical impurities or undesired side products.

[0091] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the aspects of the present invention. Thus, it should be understood that although the present invention has been specifically disclosed by specific aspects and optional features, modification and variation of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of aspects of the present invention.Exemplary Aspects.

[0092] The following exemplary aspects are provided, the numbering of which is not to be construed as designating levels of importance:

[0093] Aspect 1 provides a method of forming a substituted or unsubstituted gammalactone, the method comprising: forming a reaction mixture comprising a substituted or unsubstituted cyano(C4-Cio)alkene and / or a hydrolysis reaction product thereof, and an acid, a solid acid catalyst, or a combination thereof; and allowing the reaction mixture to react to form the substituted or unsubstituted gammalactone.

[0094] Aspect 2 provides the method of Aspect 1, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is a substituted or unsubstituted cyano(C4-Cs)alkene.

[0095] Aspect 3 provides the method of any one of Aspects 1-2, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is a monocyano(C4-Cio)alkene or a dicyano(C4-Cio)alkene.

[0096] Aspect 4 provides the method of any one of Aspects 1-3, wherein the (C4- Cio)alkene of the substituted or unsubstituted cyano(C4-Cio)alkene is butene or pentene.

[0097] Aspect 5 provides the method of any one of Aspects 1-4, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is substituted or unsubstituted dicyanobutene and the substituted or unsubstituted gamma-lactone is substituted or unsubstituted 2-(5-oxotetrahydrofuran-2-yl)acetic acid.

[0098] Aspect 6 provides the method of any one of Aspects 1-5, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is substituted or unsubstituted 2- pentenenitrile and the substituted or unsubstituted gamma-lactone is substituted or unsubstituted gamma-valerolactone.

[0099] Aspect 7 provides the method of any one of Aspects 1-6, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is substituted or unsubstituted 3- pentenenitrile and the substituted or unsubstituted gamma-lactone is substituted or unsubstituted gamma-valerolactone.

[0100] Aspect 8 provides the method of any one of Aspects 1-7, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is substituted or unsubstituted 2-methyl-3- butenenitrile and the substituted or unsubstituted gamma-lactone is substituted or unsubstituted alpha-methyl-gamma-butyrolactone.

[0101] Aspect 9 provides the method of any one of Aspects 1-8, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is unsubstituted.

[0102] Aspect 10 provides the method of any one of Aspects 1-9, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is dicyanobutene, 2-pentenenitrile, 3- pentenenitrile, 2-methyl-3 -butenenitrile, or a mixture thereof.

[0103] Aspect 11 provides the method of any one of Aspects 1-10, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is 2-pentenenitrile, 3 -pentenenitrile, or a mixture thereof.

[0104] Aspect 12 provides the method of any one of Aspects 1-11, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is 3 -pentenenitrile.

[0105] Aspect 13 provides the method of any one of Aspects 1-12, wherein the reaction mixture comprises the substituted or unsubstituted cyano(C4-Cio)alkene.

[0106] Aspect 14 provides the method of any one of Aspects 1-13, wherein the reaction mixture comprises the hydrolysis product of the substituted or unsubstituted cyano(C4-Cio)alkene.

[0107] Aspect 15 provides the method of Aspect 14, wherein the hydrolysis product comprises a reaction product of basic hydrolysis of the substituted or unsubstituted cyano(C4- Cio)alkene.

[0108] Aspect 16 provides the method of any one of Aspects 1-15, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is a substituted 3 -pentenenitrile, wherein the gamma-lactone is substituted, wherein the 3 -pentenenitrile has the structure:wherein the gamma-lactone has the structure:whereinR’-R6are each independently chosen from -H and Rs, at each occurrence, Rsis independently chosen from halide, a substituted or unsubstituted (Ci-Cio)hydrocarbyl, and a (C2-Cio)hydrocarbyl optionally interrupted with 1, 2, or 3 groups chosen from -O-, -S-, and -NH-, and at least one of R’-R6is Rs.

[0109] Aspect 17 provides the method of Aspect 16, wherein one of R’-R6is Rs.

[0110] Aspect 18 provides the method of Aspect 16, wherein two of R’-R6is Rs.

[0111] Aspect 19 provides the method of Aspect 16, wherein three of R’-R6is Rs.

[0112] Aspect 20 provides the method of any one of Aspects 16-19, wherein Rsis halide.

[0113] Aspect 21 provides the method of any one of Aspects 16-20, wherein Rsis unsubstituted (Ci-Cio)hydrocarbyl.

[0114] Aspect 22 provides the method of any one of Aspects 1-15, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is unsubstituted 3 -pentenenitrile and wherein the gamma-lactone is unsubstituted.

[0115] Aspect 23 provides the method of any one of Aspects 1-22, wherein the reaction mixture is an aqueous mixture.

[0116] Aspect 24 provides the method of any one of Aspects 1-23, wherein the reaction mixture is substantially free of 4-pentenenitrile.

[0117] Aspect 25 provides the method of any one of Aspects 1-24, wherein 4- pentenenitrile is less than 2 wt% of the reaction mixture.

[0118] Aspect 26 provides the method of any one of Aspects 1-25, wherein the reaction mixture comprises the acid, wherein the acid comprises sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, boric acid, hydrofluoric acid, hydrobromic acid, perchloric acid, hydroiodic acid, acidic ionic liquid or a combination thereof.

[0119] Aspect 27 provides the method of Aspect 26, wherein the acid comprises sulfuric acid or phosphoric acid.

[0120] Aspect 28 provides the method of any one of Aspects 1-27, wherein the acid is 10 wt% to 98 wt% of the reaction mixture.

[0121] Aspect 29 provides the method of any one of Aspects 1-28, wherein the acid is 30 wt% to 95 wt% of the reaction mixture.

[0122] Aspect 30 provides the method of any one of Aspects 1-29, wherein the acid is 70 wt% to 95 wt% of a total amount of the acid and the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof in the reaction mixture.

[0123] Aspect 31 provides the method of any one of Aspects 1-30, wherein the acid is 50 wt% to 98 wt% of a total amount of the acid and the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof in the reaction mixture.

[0124] Aspect 32 provides the method of any one of Aspects 1-31, wherein the reaction mixture comprises the solid acid catalyst, wherein the solid acid catalyst comprises a zeolite, a sulfated metal oxide, mixed metal oxide, doped silica, an acid treated clay, an acidic metal-organic framework, an acidic carbon-organic framework, a heteropolyacid, a solid superacid, a mesoporous material, an ion-exchange resin, or a combination thereof.

[0125] Aspect 33 provides the method of any one of Aspects 1-32, wherein the reaction mixture comprises the solid acid catalyst, wherein the solid acid catalyst comprises a zeolite (e.g., ZSM-5), an ion-exchange resin (e.g., Amberlyst), tungstated zirconia, a silicoaluminophosphate (e.g., SAPO 34), a perfluorosulfonic acid polymer (e.g., Nafion resin), a solid acid, solid phosphoric acid, sulfonated zirconia, montmorillonite, or a combination thereof.

[0126] Aspect 34 provides the method of Aspect 33, wherein the solid acid catalyst comprises an ion-exchange resin, a zeolite, tungstated zirconia, or a combination thereof.

[0127] Aspect 35 provides the method of any one of Aspects 1-34, wherein the solid acid catalyst is 0.001 wt% to 90 wt% of the reaction mixture.

[0128] Aspect 36 provides the method of any one of Aspects 1-35, wherein the solid acid catalyst is 30 wt% to 80 wt% of the reaction mixture.

[0129] Aspect 37 provides the method of any one of Aspects 1-36, wherein the solid acid catalyst is 0.001 wt% to 95 wt% of a total amount of the solid acid catalyst and the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof in the reaction mixture.

[0130] Aspect 38 provides the method of any one of Aspects 1-37, wherein the solid acid catalyst is 60 wt% to 90 wt% of a total amount of the solid acid catalyst and the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof in the reaction mixture.

[0131] Aspect 39 provides the method of any one of Aspects 1-38, wherein the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof is 0.01 wt% to 50 wt% of the reaction mixture.

[0132] Aspect 40 provides the method of any one of Aspects 1-39, wherein the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof is 1 wt% to 20 wt% of the reaction mixture.

[0133] Aspect 41 provides the method of any one of Aspects 1-40, wherein the reaction mixture further comprises a solvent.

[0134] Aspect 42 provides the method of Aspect 41, wherein the solvent is water, an organic solvent, an alcohol, or a combination thereof.

[0135] Aspect 43 provides the method of Aspect 41, wherein the solvent is water.

[0136] Aspect 44 provides the method of any one of Aspects 41-43, wherein the solvent is 0.001 wt% to 90 wt% of the reaction mixture.

[0137] Aspect 45 provides the method of any one of Aspects 41-44, wherein the solvent is 30 wt% to 60 wt% of the reaction mixture.

[0138] Aspect 46 provides the method of any one of Aspects 1-45, wherein forming the reaction mixture comprises forming the reaction mixture at -20 °C to 100 °C.

[0139] Aspect 47 provides the method of any one of Aspects 1-46, wherein forming the reaction mixture comprises forming the reaction mixture at -10 °C to 30 °C.

[0140] Aspect 48 provides the method of any one of Aspects 1-47, wherein forming the reaction mixture comprises forming the reaction mixture at about room temperature.

[0141] Aspect 49 provides the method of any one of Aspects 1-48, wherein forming the reaction mixture comprises forming the reaction mixture at about 0 °C.

[0142] Aspect 50 provides the method of any one of Aspects 1-49, wherein the forming of the reaction mixture comprises maintaining the reaction mixture at a temperature of -10 °C to about 10 °C during the formation thereof.

[0143] Aspect 51 provides the method of any one of Aspects 1-50, wherein the forming of the reaction mixture comprises maintaining the reaction mixture at a temperature of 0 °C during the formation thereof.

[0144] Aspect 52 provides the method of any one of Aspects 1-51, wherein forming the reaction mixture comprises cooling the reaction mixture to maintain or decrease a temperature thereof.

[0145] Aspect 53 provides the method of any one of Aspects 1-52, wherein reacting the reaction mixture comprises heating the reaction mixture to a reaction temperature for a heating duration.

[0146] Aspect 54 provides the method of Aspect 53, wherein the reaction temperature is 20 °C to 400 °C.

[0147] Aspect 55 provides the method of Aspect 53, wherein the reaction temperature is 40 °C to 90 °C.

[0148] Aspect 56 provides the method of any one of Aspects 53-55, wherein the reaction duration is 10 minutes to 240 h.

[0149] Aspect 57 provides the method of any one of Aspects 53-56, wherein the reaction duration is 30 minutes to 5 h.

[0150] Aspect 58 provides the method of any one of Aspects 1-57, wherein the reacting of the reaction mixture is performed at about ambient pressure.

[0151] Aspect 59 provides the method of any one of Aspects 1-58, wherein the method forms the gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene at a yield of 50% to 100%.

[0152] Aspect 60 provides the method of any one of Aspects 1-59, wherein the method forms the gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene at a yield of 95% to 100%.

[0153] Aspect 61 provides the method of any one of Aspects 1-60, wherein the method has a percent conversion of the substituted or unsubstituted cyano(C4-Cio)alkene of 80% to 100%.

[0154] Aspect 62 provides the method of any one of Aspects 1-61, wherein the method has a percent conversion of the substituted or unsubstituted cyano(C4-Cio)alkene of 95% to 100%.

[0155] Aspect 63 provides the method of any one of Aspects 1-62, further comprising neutralizing remaining acid in the substituted or unsubstituted gamma-lactone, or removing solid acid catalyst from the substituted or unsubstituted gamma-lactone.

[0156] Aspect 64 provides the method of any one of Aspects 1-63, further comprising extracting the substituted or unsubstituted gamma-lactone into an organic solvent.

[0157] Aspect 65 provides the method of Aspect 64, wherein the organic solvent comprises ethyl acetate, dichloromethane, or a combination thereof.

[0158] Aspect 66 provides the method of any one of Aspects 1-65, wherein the substituted or unsubstituted gamma-lactone is substantially free of byproducts.

[0159] Aspect 67 provides the method of any one of Aspects 1-66, wherein byproducts are 0 wt% to 10 wt% of the produced substituted or unsubstituted gamma-lactone.

[0160] Aspect 68 provides the method of any one of Aspects 1-67, wherein byproducts are 0 wt% to 2 wt% of the produced substituted or unsubstituted gamma-lactone.

[0161] Aspect 69 provides the method of any one of Aspects 1-68, wherein the reaction mixture further comprises a metallic catalyst.

[0162] Aspect 70 provides the method of Aspect 69, wherein the method comprises dissolving the metallic catalyst in the reaction mixture.

[0163] Aspect 71 provides the method of any one of Aspects 69-70, wherein the metallic catalyst comprises a metal sulfate catalyst, a nickel catalyst, a zinc catalyst, a copper catalyst, nickel sulfate, zinc sulfate, copper sulfate, a hydrate thereof, or a combination thereof.

[0164] Aspect 72 provides the method of any one of Aspects 69-71, wherein the metallic catalyst comprises copper sulfate or a hydrate thereof.

[0165] Aspect 73 provides the method of any one of Aspects 69-72, wherein the metallic catalyst is 0.1 wt% to 20 wt% of the reaction mixture.

[0166] Aspect 74 provides the method of any one of Aspects 69-73, wherein the metallic catalyst is 1 wt% to 15 wt% of the reaction mixture.

[0167] Aspect 75 provides the method of any one of Aspects 69-74, wherein reacting the reaction mixture comprises heating the reaction mixture to a reaction temperature of 40 °C to 400 °C for a heating duration of 30 minutes to 10 h.

[0168] Aspect 76 provides the method of any one of Aspects 69-75, wherein the method forms the gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene at a yield of 80% to 100%.

[0169] Aspect 77 provides the method of any one of Aspects 69-76, wherein the method forms the gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene at a yield of 95% to 100%.

[0170] Aspect 78 provides the method of any one of Aspects 69-77, wherein the method has a percent conversion of the substituted or unsubstituted cyano(C4-Cio)alkene of 80% to 100%.

[0171] Aspect 79 provides the method of any one of Aspects 69-78, wherein the method has a percent conversion of the substituted or unsubstituted cyano(C4-Cio)alkene of 95% to 100%.

[0172] Aspect 80 provides the method of any one of Aspects 69-79, wherein byproducts are 0 wt% to 10 wt% of the produced substituted or unsubstituted gamma-lactone.

[0173] Aspect 81 provides the method of any one of Aspects 69-80, wherein byproducts are 0 wt% to 2 wt% of the produced substituted or unsubstituted gamma-lactone.

[0174] Aspect 82 provides the method of any one of Aspects 1-81, wherein the method comprises performing the reacting of the reaction mixture in a continuous reactor.

[0175] Aspect 83 provides the method of any one of Aspects 1-82, wherein the method comprises performing the reacting of the reaction mixture in a batch reactor.

[0176] Aspect 84 provides a method of forming a substituted or unsubstituted gamma-valerolactone, the method comprising: forming a reaction mixture comprising a substituted or unsubstituted 3 -pentenenitrile and / or a hydrolysis reaction product thereof, and an acid, a solid acid catalyst, or a combination thereof; and allowing the reaction mixture to react to form the substituted or unsubstituted gamma- valerolactone.

[0177] Aspect 85 provides a method of forming gamma-valerolactone, the method comprising: forming a reaction mixture comprising3 -pentenenitrile, and an acid, a solid acid catalyst, or a combination thereof; and heating the reaction mixture to 20 °C to 400 °C for 30 minutes to 5 h at ambient pressure to form the gamma-valerolactone with a yield of 95% to 100% and a conversion of the 3 -pentenenitrile of 95% to 100%.

[0178] Aspect 86 provides a method of forming gamma-valerolactone, the method comprising: forming a reaction mixture comprising3 -pentenenitrile, and an acid, and a metallic catalyst comprising nickel sulfate, copper sulfate, zinc sulfate, a hydrate thereof, or a combination thereof; heating the reaction mixture to 40 °C to 90 °C for 30 minutes to 5 hours at ambient pressure to form the gamma-valerolactone with a yield of 95% to 100% and a conversion of the 3 -pentenenitrile of 95% to 100%.

[0179] Aspect 87 provides a substituted or unsubstituted cyano(C4-Cio)alkene for use in the method of any one of Aspects 1-86.

[0180] Aspect 88 provides the substituted or unsubstituted cyano(C4-Cio)alkene of Aspect 87, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is 2-methyl-3- butenenitrile, 3 -pentenenitrile, 2-pentenenitrile, or a combination thereof.

[0181] Aspect 89 provides the substituted or unsubstituted cyano(C4-Cio)alkene of Aspect 88, wherein the 2-methyl-3 -butenenitrile, 3 -pentenenitrile, or 2-pentenenitrile is a product of hydrocyanation of butadiene.

[0182] Aspect 90 provides the method or substituted or unsubstituted cyano(C4- Cio)alkene of any one or any combination of Aspects 1-73 optionally configured such that all elements or options recited are available to use or select from.

[0183] Aspect 91 provides the method of any one of Aspects 1-90, wherein the method comprises introducing a gas for sparging the reaction mixture.

[0184] Aspect 92 provides the method of Aspect 91, wherein the gas for sparging the reaction mixture is selected from the group consisting of nitrogen, helium, argon, carbon dioxide, carbon monoxide, and steam.

[0185] Aspect 93 provides the method of any one of Aspects 91-92, wherein the gas for sparging the reaction mixture comprises a Lewis acid component.

[0186] Aspect 94 provides the method of any one of Aspects 1 through 90, wherein the method comprises a catalyst activity recovery step, such as including increasing the temperature of the reaction to increase yield of gamma-valerolactone.

[0187] Aspect 95 provides an as-produced reaction product of 3 -pentenenitrile comprising gamma-valerolactone and >0 wt.% to <1 wt.% of components other than gamma- valerolactone.

[0188] Aspect 96 provides an as-produced reaction product of Aspect 95, wherein the components other than gamma-valerolactone are selected from the group consisting of alphaangelica lactone, furfural -propyl ether, 2-methyl-tetrahydrofuran, 2-butanol, 2-pentanol, 1,4- pentanediol, heavy acid, furfuryl alcohol resin, furfural, 4-cyclopentene-l, 3-dione, propylmalonic acid, pentyl-cyclopropane, 2-cyclopenten-l-one, 5-methyl-2(3H)-furanone, 2- hexyl cyclopentanone, tetrahydro furfuryl alcohol, trans-2-undecen-l-ol, pentanoic acid, levulinic acid or its alkyl (e.g., methyl, ethyl, or iso-propyl) esters, furfuryl alcohol, 4- hydroxyvaleric acid, and combinations thereof.

[0189] Aspect 97 provides a reaction product of any one of Aspects 95-96, wherein the components other than gamma-valerolactone are present in the as-produced reaction product at concentrations selected from 0 wt%, 0 wt% to 0.1 wt%, 0 wt% to 0.001 wt%, < 1 wt.%, < 0.25 wt.%, < 0.1 wt.%, < 500 ppmw, < 100 ppmw, < 50 ppmw, < 30 ppmw, < 10 ppmw, < 50 ppmw, < 1 ppmw, < 0.5 ppmw, and < 0.1 ppmw of the total composition.

[0190] Aspect 98 provides the reaction product of any one of Aspects 95-97 wherein the concentration of one or more of the components other than gamma-valerolactone is undetectable using commercially available analytical techniques.

[0191] Aspect 99 provides the reaction product of any one of Aspects 95-98, wherein the reaction product has had catalyst removed therefrom.

[0192] Aspect 100 provides the method or as-produced reaction product of any one or any combination of Aspects 1-99 optionally configured such that all elements or options recited are available to use or select from.

Claims

CLAIMSWhat is claimed is:

1. A method of forming a substituted or unsubstituted gamma-lactone, the method comprising: forming a reaction mixture comprising a substituted or unsubstituted cyano(C4-Cio)alkene and / or a hydrolysis reaction product thereof, and an acid, a solid acid catalyst, or a combination thereof; and allowing the reaction mixture to react to form the substituted or unsubstituted gammalactone.

2. The method of claim 1, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is a substituted or unsubstituted cyano(C4-Cs)alkene.

3. The method of claim 1, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is dicyanobutene, 2-pentenenitrile, 3 -pentenenitrile, 2-methyl-3 -butenenitrile, or a mixture thereof.

4. The method of claim 1, wherein the reaction mixture comprises the hydrolysis product of the substituted or unsubstituted cyano(C4-Cio)alkene, wherein the hydrolysis product comprises a reaction product of basic hydrolysis of the substituted or unsubstituted cyano(C4-Cio)alkene.

5. The method of claim 1, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is a substituted 3 -pentenenitrile, wherein the gamma-lactone is substituted, and wherein the 3- pentenenitrile has the structure:wherein the gamma-lactone has the structure:whereinR’-R6are each independently chosen from -H and Rs, at each occurrence, Rsis independently chosen from halide, a substituted or unsubstituted (Ci-Cio)hydrocarbyl, and a (C2-Cio)hydrocarbyl optionally interrupted with 1, 2, or 3 groups chosen from -O-, -S-, and -NH-, and at least one of R’-R6is Rs.

6. The method of claim 1, wherein the substituted or unsubstituted cyano(C4-Cio)alkene is unsubstituted 3 -pentenenitrile and wherein the gamma-lactone is unsubstituted.

7. The method of claim 1, wherein the reaction mixture comprises the acid, wherein the acid comprises sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, boric acid, hydrofluoric acid, hydrobromic acid, perchloric acid, hydroiodic acid, acidic ionic liquid, or a combination thereof, and wherein the acid is 10 wt% to 98 wt% of the reaction mixture.

8. The method of claim 1, wherein the reaction mixture comprises the solid acid catalyst, wherein the solid acid catalyst comprises a zeolite, a sulfated metal oxide, mixed metal oxide, doped silica, an acid treated clay, an acidic metal-organic framework, an acidic carbonorganic framework, a heteropolyacid, a solid superacid, a mesoporous material, an ionexchange resin, or a combination thereof, and wherein the solid acid catalyst is 0.001 wt% to 90 wt% of the reaction mixture.

9. The method of claim 1, wherein the substituted or unsubstituted cyano(C4-Cio)alkene or hydrolysis product thereof is 0.01 wt% to 50 wt% of the reaction mixture.

10. The method of claim 1, wherein the reaction mixture further comprises a solvent, wherein the solvent comprises water, an organic solvent, an alcohol, or a combination thereof, wherein the solvent is 0.001 wt% to 90 wt% of the reaction mixture.

11. The method of claim 1, wherein the forming of the reaction mixture comprises maintaining the reaction mixture at a temperature of -10 °C to about 10 °C during the formation thereof.

12. The method of claim 1, wherein reacting the reaction mixture comprises heating the reaction mixture to a reaction temperature of 20 °C to 400 °C for a heating duration of 30 minutes to 5 h.

13. The method of claim 1, wherein the method forms the gamma-lactone from the substituted or unsubstituted cyano(C4-Cio)alkene at a yield of 95% to 100% and has a percent conversion of the substituted or unsubstituted cyano(C4-Cio)alkene of 95% to 100%.

14. The method of claim 1, wherein byproducts are 0 wt% to 2 wt% of the produced substituted or unsubstituted gamma-lactone.

15. The method of claim 1, wherein the reaction mixture further comprises a metallic catalyst, wherein the method comprises dissolving the metallic catalyst in the reaction mixture, wherein the metallic catalyst is 0.1 wt% to 20 wt% of the reaction mixture.

16. The method of claim 15, wherein the metallic catalyst comprises a metal sulfate catalyst, a nickel catalyst, a zinc catalyst, a copper catalyst, nickel sulfate, zinc sulfate, copper sulfate, a hydrate thereof, or a combination thereof.

17. The method of claim 15, wherein the metallic catalyst comprises copper sulfate or a hydrate thereof.

18. The method of claim 1, the method further comprising introducing a gas for sparging the reaction mixture.

19. A method of forming gamma-valerolactone, the method comprising: forming a reaction mixture comprising3 -pentenenitrile, and an acid, anda metallic catalyst comprising nickel sulfate, copper sulfate, zinc sulfate, a hydrate thereof, or a combination thereof; heating the reaction mixture to 20 °C to 400 °C for 30 minutes to 5 hours at ambient pressure to form the gamma-valerolactone.

20. An as-produced reaction product of 3 -pentenenitrile comprising gamma-valerolactone and >0 wt.% to <1 wt.% of components other than gamma-valerolactone.

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