Cyclic hydrocarbon, method for producing same, and use thereof

Abstract

The present invention addresses the problem of providing: a novel cyclic hydrocarbon; a method for producing the cyclic hydrocarbon; and a use of the cyclic hydrocarbon. The means for solving the problem is a cyclic hydrocarbon represented by general formula (I), a method for producing the same and a use thereof.　Formula (I): [CH2-CH(CH3)=CH-CH2]m (In the formula, m is an integer of 4 to 15 and has a structure in which both ends are bonded to each other.)

Description

Cyclic hydrocarbons, their production method, and their uses

[0001] The present invention relates to a novel cyclic hydrocarbon, a method for producing the same, and uses thereof.

[0002] Isoprene is a hydrocarbon compound that is the basic unit constituting naturally occurring terpenes. Oligomeric compounds with multiple isoprene skeletons are known to have a variety of skeleton structures, including linear and cyclic. For example, it has been reported that a 12-membered ring compound, a cyclic trimer, is produced by the trimerization of isoprene (Non-Patent Documents 1 to 3). Furthermore, regarding cyclic tetramers, a 14-membered ring compound containing a propenyl group (cembrene A, 1,5,9-trimethyl-12-(1-propen-2-yl)cyclotetradeca-1,5,9-triene), a type of diterpene, is known to be a natural product with pheromone activity (Non-Patent Document 4).

[0003] Bull. Chem. Soc. Jpn. , 1978, 51, 1158-1162J. Gen. Chem. USSR, 1987, 57, 2271-2275 Chem. -A Eur. J. , 2021, 27, 15644-15649J. Chem. Soc. , Perkin Trans. 1, 1972, 21, 2653-2658

[0004] Regarding cyclic oligomer compounds of isoprene, although a cyclic trimer of a 12-membered ring compound is known, there are few reports of cyclic compounds of tetramers or higher. Regarding cyclic tetramers, only a 14-membered ring compound, Cembrene A, is known, and there have been no reports of the production of a 16-membered ring compound in which all four isoprenes are linked in a 1,4-addition manner. Furthermore, regarding cyclic compounds of tetramers or higher, there is no known method for efficiently producing a cyclic compound in which all isoprenes are linked in a 1,4-addition manner.

[0005] Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide novel cyclic hydrocarbons, a method for producing the same, and uses thereof.

[0006] As a result of extensive research aimed at solving the above problems, the present inventors have found that cyclic hydrocarbons in which four or more isoprene molecules are all linked in a 1,4-addition manner can be produced simply and efficiently by treating an isoprene-based rubber such as natural rubber or a composition containing the same with an olefin metathesis catalyst, and have thus completed the present invention.

[0007] The gist and configuration of the present invention to solve the above problems is as follows.

[0008] <1> A cyclic hydrocarbon represented by the following general formula (I): [CH ２ -C(CH ３ )=CH-CH ２ ] ｍ (I) (wherein m is an integer of 4 or more and 15 or less, and has a structure in which both ends are bonded to each other.) <2> The cyclic hydrocarbon according to <1>, wherein, in the stereochemistry of the double bonds of the general formula (I), at least one is trans-configured and the rest are cis-configured. <3> A composition containing the cyclic hydrocarbon according to <1> or <2>. <4> A method for producing the cyclic hydrocarbon according to any one of <1> to <3> or a composition containing the same by allowing a metathesis catalyst to act on polyisoprene represented by the following general formula (II) or a composition containing the same: [CH ２ -C(CH ３ )=CH-CH ２ ] ｎ(II) (In the formula, n is an integer of 20 or more and 100,000 or less, the terminal groups are the same or different organic groups, and part of the main chain may have a crosslinked structure.) <5> The production method according to <4>, wherein the composition containing polyisoprene is a composition containing carbon black or silica. <6> The production method according to <4> or <5>, wherein the metathesis catalyst is a metathesis catalyst containing ruthenium, molybdenum, tungsten, or titanium. <7> A method for producing hydrocarbons having 10 or less carbon atoms by thermally decomposing the cyclic hydrocarbons or compositions containing same according to any one of <1> to <3>. <8> A method for producing hydrocarbons having 10 or less carbon atoms by thermally decomposing the cyclic hydrocarbons produced by the method according to <4> or <5>, or compositions containing same. <9> The production method according to <7> or <8>, wherein the hydrocarbons having 10 or less carbon atoms are isoprene. <10> The method according to any one of <7> to <9>, wherein the temperature range of the thermal decomposition is 400 to 900° C. <11> The method according to any one of <7> to <10>, wherein the thermal decomposition reaction is carried out in the presence of a catalyst.

[0009] In a preferred embodiment of the method for producing cyclic hydrocarbons of the present invention, the composition containing polyisoprene further contains sulfur. Sulfur is generally used to crosslink polyisoprene. Even in this case, the composition containing sulfur-crosslinked polyisoprene can be efficiently decomposed to produce the cyclic hydrocarbons.

[0010] In another preferred embodiment of the method for producing cyclic hydrocarbons of the present invention, the composition containing polyisoprene further contains carbon black. In this case, the composition containing polyisoprene can be efficiently decomposed to produce the cyclic hydrocarbons, and the carbon black can be reused.

[0011] According to the present invention, it is possible to provide cyclic hydrocarbons that can be used as novel functional chemicals, a method for producing the same, and uses thereof.

[0012] The cyclic hydrocarbons of the present invention, their production methods, and their uses will be illustrated and described in detail below based on their embodiments.

[0013] The cyclic hydrocarbon of the present invention is a cyclic hydrocarbon represented by the following general formula (I): [CH ２ -C(CH ３ )=CH-CH ２ ] ｍ (I) In general formula (I), m is an integer of 4 or more and 15 or less, and has a structure in which both ends are bonded to each other. In general formula (I), m is preferably an integer of 4 or more and 12 or less, more preferably an integer of 4 or more and 9 or less. In addition, the stereochemistry of the double bond may be either a cis or trans isomer, but it is preferable that the stereochemistry of at least one of the multiple double bonds in the molecule is a trans isomer.

[0014] The cyclic hydrocarbon of the present invention may be not only the cyclic hydrocarbon represented by general formula (I) but also a composition containing the cyclic hydrocarbon. The ratio of the cyclic hydrocarbon represented by general formula (I) in the composition is generally 10 to 99 mass%, preferably 20 to 99 mass%, and more preferably 30 to 99 mass%.

[0015] As a method for producing the cyclic hydrocarbon represented by the general formula (I), for example, a method of reacting a polymer having an isoprene skeleton or a composition containing the same with a metathesis catalyst can be mentioned. More specifically, a method of producing a cyclic hydrocarbon represented by the following general formula (II): [CH ２ -C(CH ３ )=CH-CH ２ ] ｎ It can be produced by reacting a metathesis catalyst with polyisoprene represented by formula (II) or a composition containing it. In formula (II), n is an integer of 20 to 100,000, preferably an integer of 20 to 50,000, and more preferably an integer of 20 to 20,000. In formula (II), the terminal groups are the same or different organic groups. The terminal organic groups are preferably hydrocarbon groups, more preferably aliphatic hydrocarbon groups.

[0016] The polyisoprene or composition containing the same also includes rubbers whose main skeleton is an isoprene unit, specific examples of which include natural rubber (NR), synthetic isoprene rubber (IR), etc. The content of polyisoprene in the rubber is not particularly limited, and is preferably, for example, in the range of 10 to 100 mass%, and more preferably in the range of 30 to 100 mass% from the viewpoint of further improving the yield of cyclic hydrocarbons.

[0017] The stereochemistry of the double bond in the isoprene skeleton of general formula (II) may be any of cis type, trans type, or a mixture thereof.

[0018] The polyisoprene of general formula (II) may have a crosslinked structure in part of the main chain, and examples of the crosslinked structure include crosslinks due to sulfur or hydrocarbons.

[0019] When the polyisoprene has a crosslinked structure with sulfur, the content of sulfur in the polyisoprene is not particularly limited, and is, for example, in the range of 0.1 to 10 parts by mass, preferably 1 to 5 parts by mass, per 100 parts by mass of polyisoprene.

[0020] The composition containing polyisoprene of general formula (II) may further contain carbon black and / or silica. The ratio of carbon black and / or silica to polyisoprene can be set as desired, but is generally in the range of 5 to 200 parts by mass, preferably 5 to 150 parts by mass, and more preferably 5 to 100 parts by mass, per 100 parts by mass of polyisoprene.

[0021] In addition to sulfur and carbon black, the polyisoprene-containing composition may contain various components commonly used in the rubber industry, such as polymer components other than polyisoprene, carbon black, fillers other than silica (such as calcium carbonate), silane coupling agents, antioxidants, softeners, processing aids, resins, surfactants, organic acids (such as stearic acid), zinc oxide (zinc white), vulcanization accelerators, and crosslinking agents other than sulfur.

[0022] On the other hand, as the metathesis catalyst to be reacted with the polyisoprene represented by general formula (II) or a composition containing the same, various conventionally known catalysts such as olefin metathesis catalysts, Grubbs catalysts, and Hoveyda-Grubbs catalysts (for example, catalysts described in the review Chem. Rev. 2010, 110, 3, 1746-1787), and various commercially available products can be used. As a commercially available Grubbs catalyst, for example, Ru(PCy) is known as a first generation catalyst. ３ ) ２ (Ind)Cl ２ [Umicore product number: M101, CAS number: 250220-36-1], Ru(PCy ３ ) ２ (benzylidene)Cl ２ [M102, 172222-30-9], Ru (PCy ３ ) ２ (Butenylidene)Cl ２ [M103, 194659-03-5], Ru (PCy ３ ) ２ (2-thienylmethylene)Cl ２ [M104, 1190427-44-1], Ru( ｉ Bu-Hoban) ２ (Ind)Cl ２ [M110, 894423-99-5], and the second generation is (SIMes)Ru(PPh ３ )(Ind)Cl ２ [M200, 340810-50-6], (SIPr)Ru(PPh ３ )(Ind)Cl ２ [M201, 1307233-23-3], (SIMes)Ru(PCy ３ )(Ind)Cl ２ [M202, 536724-67-1], (IMes) Ru(PCy ３ )(Ind)Cl ２ [M203, 254972-49-1], (SIMes)Ru(PCy ３ ) (benzylidene) Cl ２ [M204, 246047-72-3], (SIPr)Ru(PCy ３ ) (benzylidene) Cl２ [M206, 373640-75-6], (SIMes)Ru(PCy ３ ) (butenylidene) Cl ２ [M207, 253688-91-4], [(Me) ２ -IMes]Ru(PCy ３ ) (2-thienylmethylene) Cl ２ [M208, 1190427-50-9], (IMes) Ru (PCy ３ ) (2-thienylmethylene) Cl ２ [M209, 1190427-49-6], (SIMes)Ru(P(O ｉ Pr) ３ )(Ind)Cl ２ [M220, 1255536-61-8], (SIMes)Ru(py)(Ind)Cl ２ [M310, 1031262-76-6], (SIMes) ２ Ru(Ind)Cl ２ [M800, 1383684-54-5], etc. Also, as known as the third generation, (SIMes)Ru(3-BrPy) ２ Cl ２ (benzylidene) [C884, 900169-53-1] and the like.

[0023] Among these catalysts, catalysts called second generation are preferred from the viewpoint of catalytic activity, and specific examples thereof include M201, M203, M204, M206, M207, M310, etc. Furthermore, catalysts called third generation are also preferred, and specific examples thereof include C884, etc.

[0024] As the metathesis catalyst, not only catalysts having a ruthenium central metal but also catalysts having a molybdenum central metal, tungsten, titanium, etc. can be used. Examples of molybdenum-based catalysts include 2,6-diisopropylphenylimide neophylidene molybdenum(VI) bis(hexafluoro-t-butoxide) [CAS No.: 139220-25-0], 2,6-diisopropylphenylimide neophylidene molybdenum(VI) bis(t-butoxide) [126949-65-3], 2,6-diisopropylphenylimide neophylidene molybdenum(VI) bis(trifluoromethanesulfonate)dimethoxyethane adduct [126949-63-1], and 2,6-diisopropylphenylimide-neophylidene[(S)-(-)-BIPHEN]molybdenum(VI) [205815-80-1]. Catalysts made of molybdenum, tungsten, titanium, etc. generally have a central metal that is less expensive than ruthenium, and therefore may be more cost-effective than ruthenium catalysts.

[0025] The cyclic hydrocarbon represented by the general formula (I) can be obtained by allowing the metathesis catalyst to act on polyisoprene or a composition containing it.

[0026] The amount of the catalyst used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, relative to 100 parts by mass of the polyisoprene. When the amount of the catalyst used is 0.01 part by mass or more relative to 100 parts by mass of the polyisoprene, the decomposition reaction of polyisoprene proceeds efficiently, and when the amount is 5 parts by mass or less, this is preferred from the viewpoint of cost.

[0027] (Reaction Mechanism) The reaction mechanism by which a metathesis catalyst acts on polyisoprene to produce cyclic hydrocarbons is thought to be, for example, as follows (Scheme 1).

[0028]

[0029] In Scheme 1, a catalytic carbene complex interacts with the double bond of polyisoprene (P), generating a metallacycle intermediate via a four-center transition state to form a carbene complex (Q) with a catalytic metal attached to the polyisoprene terminal. The terminal carbene moiety of Q interacts with an internal double bond of the same main chain, generating a metallacycle intermediate (R) via a four-center transition state, releasing a cyclic hydrocarbon (S) and attaching a catalytic metal to the terminal, yielding a polyisoprene chain (T) with a main chain shortened by the amount of the cyclic hydrocarbon (S). Repeating this cycle of interaction of the terminal carbene moiety with the internal double bond of the same main chain allows for the continuous generation of cyclic hydrocarbons. Note that in the generation of double bonds by carbon-carbon bond cleavage of the metallacycle intermediate (R), the trans isomer is preferentially generated, resulting in the introduction of a trans double bond into the cyclic hydrocarbon (S).

[0030] (Reaction Conditions for Producing Cyclic Hydrocarbons) The reaction of reacting polyisoprene with a metathesis catalyst is preferably carried out at a temperature of 0° C. or higher and 150° C. or lower. By carrying out the reaction at 0° C. or higher, the reaction rate of polyisoprene is improved, and by carrying out the reaction at 150° C. or lower, side reactions can be suppressed. The reaction temperature is more preferably 10° C. or higher from the viewpoint of improving the reaction rate, and more preferably 100° C. or lower from the viewpoints of suppressing decomposition of the metathesis catalyst and improving the selectivity of the product.

[0031] The reaction can be carried out under any pressure, including reduced pressure, normal pressure, and increased pressure. Specifically, the reaction pressure is preferably 1 kPa to 10 MPa, more preferably 10 kPa to 1 MPa, and even more preferably 50 kPa to 500 kPa.

[0032] In the reaction of this embodiment, the metathesis catalyst may be dissolved in a solvent, and the polyisoprene or a composition containing the metathesis catalyst may be immersed in the solvent to carry out the reaction. By allowing the catalyst to act on the polyisoprene in the solvent, the reaction of the polyisoprene proceeds more easily. Any solvent that does not inhibit the decomposition reaction can be used as the solvent, and examples thereof include aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, chlorinated hydrocarbons, and ethers. More specifically, the solvent is preferably toluene, xylene, hexane, pentane, cyclohexane, cyclopentane, methylene chloride, chloroform, diethyl ether, or tetrahydrofuran (THF), with toluene and hexane being more preferred. When the solvent is selected from toluene, xylene, hexane, cyclohexane, diethyl ether, and tetrahydrofuran, the production of cyclic hydrocarbons from polyisoprene proceeds more easily.

[0033] The amount of the solvent used is preferably 5 mL or more, more preferably 10 mL or more, and preferably 100 mL or less, even more preferably 50 mL or less, per gram of the polyisoprene or composition containing it. If the amount of the solvent used is 5 mL or more per gram of the polyisoprene or composition containing it, the reaction of the polyisoprene or composition containing it will proceed more easily, and if the amount of the solvent used is 100 mL or less per gram of the polyisoprene or composition containing it, this is preferred from the standpoint of cost.

[0034] The form of the polyisoprene-containing composition is not particularly limited and may be, for example, powdered rubber. Such powdered rubber can be obtained by cutting and pulverizing used rubber products such as scrap tires. The pulverization process may include multiple steps such as a preliminary pulverization process and a fine pulverization process. Furthermore, the particle size of the powdered rubber used may be adjusted by a classification process after the pulverization process.

[0035] (Product) In the cyclic hydrocarbon production reaction of this embodiment, the cyclic hydrocarbon is produced by reacting polyisoprene or a composition containing polyisoprene with a metathesis catalyst. The cyclic hydrocarbon is basically produced as a mixture of multiple cyclic hydrocarbons with different molecular weights. Regarding the production ratio, when the reaction has progressed sufficiently, the smaller m in general formula (I) is, the higher the production ratio is generally. The total yield of cyclic hydrocarbons is typically 10 to 95%, preferably 20 to 95%, and more preferably 30 to 95%. Furthermore, when the raw material polyisoprene is a composition containing carbon black, insoluble carbon black is recovered. The recovered carbon black typically contains organic components derived from polyisoprene. The proportion of organic components in the recovered carbon black is preferably 5 to 20% by mass, more preferably 5 to 15% by mass.

[0036] <Uses of Cyclic Hydrocarbons> Because the cyclic hydrocarbons of general formula (I) are composed of an isoprene skeleton, they are thought to have similar properties to similar compounds having an isoprene skeleton, and are expected to be used in fields such as agricultural chemicals, pharmaceuticals, and fragrances. Furthermore, the cyclic hydrocarbons of general formula (I) can be efficiently subjected to thermal decomposition to produce isoprene and low-molecular-weight compounds having 10 or less carbon atoms, which are useful as polymer raw materials, for example. The production of low-molecular-weight compounds such as isoprene by thermal decomposition of the cyclic hydrocarbons of general formula (I) is described below.

[0037] (Reaction Conditions for Pyrolysis) The pyrolysis of the cyclic hydrocarbons includes a step of pyrolyzing the cyclic hydrocarbons at 400°C or higher and 900°C or lower.

[0038] By carrying out the thermal decomposition step at 400° C. or higher, the reaction rate of the cyclic hydrocarbons is improved, and by carrying out the thermal decomposition step at 900° C. or lower, undesirable side reactions can be suppressed. From the viewpoint of improving the decomposition reaction rate, the thermal decomposition temperature is preferably 500° C. or higher, more preferably 650° C. or higher, and from the viewpoint of suppressing side reactions, more preferably 850° C. or lower.

[0039] The thermal decomposition step is preferably carried out in an inert gas or water vapor atmosphere. By carrying out the thermal decomposition in an inert gas atmosphere, oxidation of the produced compounds can be suppressed. Examples of the inert gas used in the thermal decomposition step include nitrogen, carbon dioxide, argon, and helium.

[0040] The thermal decomposition step can be carried out under any of atmospheric pressure, reduced pressure, and increased pressure, but is preferably carried out under atmospheric pressure or reduced pressure from the viewpoint of promoting the progress of the reaction. When carried out under reduced pressure, the pressure is preferably 0.001 to 0.9 atm, more preferably 0.01 to 0.6 atm.

[0041] Various conventionally known types of pyrolysis reactors can be used. However, from the viewpoint of pyrolysis efficiency, a type in which the raw material is introduced into a reactor heated to a high temperature and rapidly heated to pyrolysis is preferred. An example of such a pyrolysis reactor type is the type used in pyrolysis gas chromatography (hereinafter sometimes referred to as Py-GC). In this type, the raw material is instantaneously pyrolyzed at a high temperature, thereby improving the yield of the target product. Fluidized-bed reactors using silica sand, steam, or the like as a heat transfer medium are also preferred because they can rapidly heat the raw material to the pyrolysis temperature. On the other hand, if the raw material is not instantaneously pyrolyzed, problems such as insufficient decomposition of the raw material or the raw material being distilled out of the reaction system without being decomposed can occur, resulting in a decrease in the yield of the target product.

[0042] (Catalyst for thermal decomposition) In the thermal decomposition of the cyclic hydrocarbon of general formula (I), a catalyst may be present. As such a catalyst, any catalyst, whether acidic, neutral, or basic, can be used. In addition, although inorganic solid catalysts can generally be used as the catalyst, various inorganic catalysts, such as non-porous and porous catalysts, can also be used. Examples of non-porous catalysts include MgO, CaO, BaO, Y ２ O ３ , La ２ O ３ , CeO ２ , TiO ２ , ZrO ２ , metal oxides such as ZnO, Li ２ CO ３ , Na２ CO ３ , K. ２ CO ３ , Rb ２ CO ３ , Cs ２ CO ３ Examples of porous materials include silica, alumina, zeolite, montmorillonite, activated carbon, and the like. Metal-supported silica, alumina, zeolite, montmorillonite, activated carbon, and the like can also be used. There are no particular limitations on the type of silica, alumina, zeolite, montmorillonite, activated carbon, and the like, and various commercially available acidic, neutral, and basic products can be used. Zeolites such as USY, SDUSY, beta, ZSM-5, and Y types are preferably used from the viewpoint of activity. The silica / alumina ratio of the zeolite is typically 3 to 2000, preferably 4 to 1000. Zeolites and montmorillonites that have been ion-exchanged with protons or metal cations such as Na and K are also preferably used. Furthermore, silica, alumina, activated carbon, and the like that support metals such as Ru, Co, Rh, Ir, Ni, Pd, Pt, and Cu are also preferably used. The yield and distribution of products can be changed by the type of catalyst, but a basic or neutral catalyst is preferred for the yield of isoprene, a type of diene monomer, and an acidic catalyst is preferred for the production of hydrocarbons having 4 or less carbon atoms. Two or more of the above catalysts may be used in combination.

[0043] The amount of the catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 1 part by mass or more, and is preferably 80 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 5 parts by mass or less, per part by mass of the cyclic hydrocarbon or composition containing the same. If the amount of the catalyst used is 1 part by mass or more per part by mass of the cyclic hydrocarbon or composition containing the same, the cracking reaction will proceed further, and if the amount of the catalyst used is 5 parts by mass or less per part by mass of the cyclic hydrocarbon or composition containing the same, it is preferable from the standpoint of cost.

[0044] (Pyrolysis Products of Cyclic Hydrocarbons) In the pyrolysis of cyclic hydrocarbons or compositions containing the same according to this embodiment, they are decomposed into hydrocarbons having 10 or fewer carbon atoms. By efficiently decomposing cyclic hydrocarbons into hydrocarbons having 10 or fewer carbon atoms, the yield of reusable monomers and the like is improved, further enhancing the economic and environmental value of the decomposition method. The decomposition rate of cyclic hydrocarbons is preferably 20% by mass or more, and more preferably 30% by mass or more. The hydrocarbons having 10 or fewer carbon atoms as decomposition products vary depending on the type of cyclic hydrocarbon or composition containing the cyclic hydrocarbon to be decomposed, but examples include ethylene, propylene, 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, benzene, toluene, xylene, ethylbenzene, isopropylbenzene, styrene, and limonene. Of these, isoprene is particularly valuable because it can be used as a raw material for producing polyisoprene and the like. Furthermore, other low-molecular-weight hydrocarbons can also be used as raw materials for various functional chemicals, functional polymers, and the like. The cyclic hydrocarbon of the present invention is cyclic and therefore does not contain any terminal groups, and is formed only from an isoprene skeleton, so that isoprene can be advantageously produced by thermal decomposition.

[0045] <Others> The reaction of polyisoprene or a composition containing polyisoprene according to this embodiment may include other steps in addition to the reaction step using the metathesis catalyst and the thermal decomposition step. Examples of such steps include pretreatment steps (e.g., a cutting step or a pulverization step) of polyisoprene or a composition containing polyisoprene. Furthermore, the reaction for producing cyclic hydrocarbons and the thermal decomposition reaction of cyclic hydrocarbons according to this embodiment can be carried out in any type of reactor, such as a batch reactor or a flow reactor.

[0046] <Separation and Purification of Products> Regarding separation and purification of the products after the reaction, in the cyclic hydrocarbon production process, separation and purification can be easily performed by procedures such as filtration, centrifugation, reprecipitation, column chromatography, and preparative gel permeation chromatography (hereinafter sometimes referred to as GPC), and in the cyclic hydrocarbon thermal decomposition process, by procedures such as distillation and recrystallization. For example, in the cyclic hydrocarbon production process, when a compounded rubber of vulcanized natural rubber and carbon black is used as the raw material, the insoluble carbon black after the reaction can be easily separated and recovered by centrifugation or filtration. Furthermore, column chromatography using silica gel, Florisil, or the like as a carrier can remove most of the metathesis catalyst and minor components such as antioxidants in the compounded rubber. Florisil is particularly effective for separating and recovering coloring components such as catalysts, and colorless cyclic hydrocarbons can be obtained by using a Florisil column using toluene or a toluene / hexane mixed solution as an eluent. When using column chromatography using silica gel, Florisil, or the like, most of the metathesis catalyst and its decomposition products are adsorbed onto the carrier, allowing valuable resources such as catalyst metals to be recovered and reused.

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0048] <Analytical devices, etc.> Gel permeation chromatography (hereinafter sometimes referred to as GPC): Analysis system: LabSolutions manufactured by Shimadzu Corporation (liquid delivery unit: LC-20AB manufactured by Shimadzu Corporation, column: G2000HXL+G4000HXL manufactured by Tosoh Corporation, detector: differential refractometer RID-10A manufactured by Shimadzu Corporation, eluent: tetrahydrofuran, flow rate: 1.0 mL / min, measurement temperature: 40°C, standard polystyrene standard) Recycle preparative gel permeation chromatography (hereinafter sometimes referred to as recycle preparative GPC): LaboACE LC-5060 Plus II manufactured by Japan Analytical Industry Co., Ltd. (column: JAIGEL-2HR Plus manufactured by Japan Analytical Industry Co., Ltd., eluent: toluene, flow rate: 10 mL / min) Nuclear magnetic resonance analyzer (hereinafter sometimes referred to as NMR): AVANCE III manufactured by Bruker HD 600 (solvent: CDCl３ ) Pyrolyzer device (hereinafter may be referred to as Py): PY-3030D manufactured by Frontier Labs Gas chromatograph mass spectrometer (hereinafter may be referred to as GC / MS): GCMS-QP2010Plus manufactured by Shimadzu Corporation (Column: UltraALLOY UA-1 capillary column manufactured by Frontier Labs) Gas chromatograph analyzer (hereinafter may be referred to as GC): GC-2014 manufactured by Shimadzu Corporation (Column: UltraALLOY UA-1 capillary column manufactured by Frontier Labs) It should be noted that a pyrolyzer device is generally used by being attached to a gas chromatography mass spectrometer or a gas chromatograph analyzer (hereinafter may be referred to as Py-GC / MS or Py-GC).

[0049] <Preparation of Raw Rubber Sample A> 100 parts by mass of natural rubber was blended with 50 parts by mass of carbon black, 2 parts by mass of stearic acid, 2.25 parts by mass of zinc oxide, 2 parts by mass of antioxidant 6PPD [N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine], 0.6 parts by mass of vulcanization accelerator (N-cyclohexyl-2-benzothiazolylsulfenamide), 1.8 parts by mass of sulfur, and 1 part by mass of antioxidant TMDQ (trimethyldihydroquinoline polymer) to prepare a rubber composition, which was then heat-crosslinked to prepare a vulcanized rubber. The resulting vulcanized rubber was cut to approximately 2-6 mm on a side and freeze-pulverized to prepare a powdered raw rubber sample (approximately 1 mm on a side).

[0050] <Examples of Cyclic Hydrocarbon Production> (Example 1) 5 mL of toluene was added to 125 mg of the raw rubber sample A and 8 mg of metathesis catalyst M204 (M204 manufactured by Unicor, Merck product number 569747), and the mixture was stirred at 25°C for 24 hours. After the reaction, toluene was added, and the carbon black was separated by centrifugation. The filtrate and the washings obtained by washing the carbon black with toluene were combined and concentrated under reduced pressure, resulting in 84 mg of composition (Ia) containing cyclic hydrocarbons (see Table 1). A portion of (Ia) was sampled and １H NMR analysis revealed that the proportion of isoprene skeletons containing cyclic hydrocarbons was 76%, and the yield of isoprene components was 88%. GPC analysis revealed that the component ratios of cyclic hydrocarbons (m = 4, 5, 6, 7, 8-15) were 36:12:7:6:20, respectively.

[0051] Examples 2 to 11 The reaction conditions (amount of catalyst, type of solvent) were changed, and the reaction and analysis of the products were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0052]

[0053] (Notes for Table 1) 1) The catalysts used were as follows: M204: (SIMes)Ru(PCy ３ ) (benzylidene) Cl ２ (Unicor M204, Merck product number 569747). 2) The solvents used were as follows: PhMe: toluene, HexH: hexane, Et ２ O: diethyl ether, THF: tetrahydrofuran, CH ２ Cl ２ : methylene chloride, cycHex: cyclohexane. 3) The IP skeleton ratio is １ This shows the proportion of isoprene skeletons calculated by H NMR. 4) Yield is the yield of isoprene skeleton products relative to the polyisoprene components in the raw rubber sample, and was calculated using the following formula: Yield (%) = [Product weight (mg) × IP skeleton proportion (%)] / Amount of polyisoprene component in raw rubber (mg) Note that, when natural rubber is used as the raw rubber, the amount of polyisoprene component in the raw rubber was calculated assuming that the polyisoprene component in the natural rubber accounted for 93%. In the case of rubber sample A, this was calculated using the following formula: Amount of polyisoprene component (mg) = Weight of rubber sample A (mg) × 0.626 (proportion of natural rubber component in rubber sample A) × 0.93 (proportion of polyisoprene in natural rubber) 5) This shows the proportion (%) of the area of ​​each cyclic hydrocarbon component to the area of ​​all components, including the polyisoprene component, in the chromatogram obtained by GPC measurement. Note that the numerical values ​​for components where m = 8-15 include values ​​that include components other than cyclic hydrocarbons.

[0054] Example 12 125 mg of synthetic cis-polyisoprene and 12 mg of metathesis catalyst M204 (M204 manufactured by Unicor, Merck product number 569747) were added with 5 mL of toluene and stirred for 24 hours at 25°C under a nitrogen atmosphere. After the reaction, 13 mg of 1,4-bis(3-isocyanopropyl)piperazine was added to inactivate the catalyst, and the solid component was separated by passing through a silica gel pad. The resulting solution was combined with the washings obtained by washing the silica gel pad with toluene and concentrated under reduced pressure to obtain 136 mg of composition (Ia') containing cyclic hydrocarbons (see Table 2). A portion of composition (Ia') was sampled and １ H NMR analysis revealed that the proportion of isoprene skeletons containing cyclic hydrocarbons was 84%, and the yield of isoprene components was 92%. GC analysis revealed that the yields of tetramers and pentamers of the cyclic hydrocarbons were 27% and 14%, respectively.

[0055] Example 13 The reaction and analysis of the product were carried out in the same manner as in Example 12, except that 125 mg of natural rubber was used instead of the synthetic cis-polyisoprene. The results are shown in Table 2.

[0056] Example 14 5 mL of toluene was added to 125 mg of the raw rubber sample A and 8 mg of the metathesis catalyst M204, and the mixture was stirred at 25°C under a nitrogen atmosphere for 24 hours. After the reaction, 5 mL of methanol was added to inactivate the catalyst, toluene was added, and the carbon black was separated by centrifugation. The filtrate and the washings obtained by washing the carbon black with toluene were combined and concentrated under reduced pressure, resulting in 90 mg of a composition (Ic') containing cyclic hydrocarbons (see Table 2). A portion of the composition (Ic') was sampled and １ H NMR analysis revealed that the proportion of isoprene skeletons derived from cyclic hydrocarbons was 79%, and the yield of isoprene components was 90%. GC analysis revealed that the yields of tetramers and pentamers of the cyclic hydrocarbons were 37% and 17%, respectively.

[0057] Examples 15 to 17 The catalyst was changed, and the reaction and analysis of the product were carried out in the same manner as in Example 14. The results are shown in Table 2.

[0058]

[0059] (Notes for Table 2) 1) The catalysts used were as follows: M204: (SIMes)Ru(PCy ３ ) (benzylidene) Cl ２ (Unicor M204, Merck product number 569747). M300: (SIMes)Ru(3-bromopyridine) ２ (3-phenylmethylene)Cl ２ (Merck product number 682330). M202: (SIMes)Ru(PCy ３ )(3-phenyl-1H-inden-1-ylidene)Cl ２ (Unicor M202, Merck product number 775258). M207: (SIMes)Ru(PCy ３ ) (3-methyl-2-butenylidene)Cl ２ (Unicor M207, Merck product number 682365). 2) The IP skeleton ratio is １ 1H NMR。 3) Yield is the yield of the isoprene skeleton product relative to the polyisoprene component in the raw rubber sample, and was calculated using the following formula: Yield (%) = [Product weight (mg) × IP skeleton ratio (%)] / Amount of polyisoprene component in raw rubber (mg) When natural rubber is used as the raw rubber, the amount of polyisoprene component in the raw rubber was calculated assuming that the polyisoprene component in the natural rubber accounted for 93%, and in the case of rubber sample A, it was calculated using the following formula: Amount of polyisoprene component (mg) = Weight of rubber sample A (mg) × 0.626 (proportion of natural rubber component in rubber sample A) × 0.93 (proportion of polyisoprene in natural rubber) 4) GC measurement (FID detector) was performed on a toluene solution to which mesitylene was added as an internal standard, and the yield of the tetramer and the yield of the pentamer were calculated using the absolute calibration curve method and the effective carbon number method, respectively.

[0060] (Example 18) 100 mL of tetrahydrofuran was added to 2.5 g of the raw rubber sample A and 160 mg of metathesis catalyst M204 (M204 manufactured by Unicor, Merck product number 569747), and the mixture was stirred at 25°C for 24 hours. After the reaction, the carbon black was separated by filtration, and the filtrate and the washings obtained by washing the carbon black with tetrahydrofuran were combined and concentrated under reduced pressure, resulting in 2.5 g of composition (Il) containing cyclic hydrocarbons. A portion of (Il) was sampled and １ As a result of measuring H NMR and GPC, １ From H NMR, the proportion of isoprene skeletons mainly derived from cyclic hydrocarbons was 74%, and from GPC, the component ratio of cyclic hydrocarbons (m=4, 5, 6, 7, 8-15) was calculated to be 38:9:5:4:17, respectively.

[0061] A portion (0.40 g) of (Il) was dissolved in toluene, and the cyclic hydrocarbons were purified by silica gel chromatography (eluent: toluene / hexane=1 / 1). As a result, a brown liquid composition (Il) P1 containing cyclic hydrocarbons was obtained (0.30 g). １ H NMR indicated that the proportion of isoprene skeletons derived mainly from cyclic hydrocarbons was 89%, and GPC calculated that the component ratios of cyclic hydrocarbons (m = 4, 5, 6, 7, 8-15) were 39:10:6:5:16, respectively. Furthermore, a portion (0.40 g) of (Il) was dissolved in toluene, and the cyclic hydrocarbons were purified by Florisil chromatography (eluent: toluene / hexane = 1 / 3). As a result, a colorless liquid composition (Il) P2 containing cyclic hydrocarbons was obtained (0.256 g). １ From H NMR, the proportion of isoprene skeletons mainly derived from cyclic hydrocarbons was 94%, and from GPC, the component ratio of cyclic hydrocarbons (m=4, 5, 6, 7, 8-15) was calculated to be 43:12:7:5:18, respectively.

[0062] The results of elemental analysis (C, H) of (Il), (Il)P1, and (Il)P2 and the calculated values ​​for (I) are shown below: (Il): C 83.5, H 11.2 (Il)P1: C 86.5, H 11.6 (Il)P2: C 87.6, H 11.9 (I): C 88.16, H 11.84 These results show that as the degree of purification increases, from unpurified (Il) to silica gel-purified (Il)P1 and Florisil-purified (Il)P2, the elemental analysis values ​​of the products approach and nearly match the calculated values ​​for general formula (I).

[0063] (Example 19) 100 mL of toluene was added to 2.5 g of the raw rubber sample A and 160 mg of metathesis catalyst M204 (M204 manufactured by Unicor, Merck product number 569747), and the mixture was stirred at 25°C for 24 hours. After the reaction, the carbon black was separated by filtration, and the filtrate and the washings obtained by washing the carbon black with toluene were combined and concentrated under reduced pressure, resulting in 1.6 g of a composition (Im) containing cyclic hydrocarbons. A portion of (Im) was sampled and １ As a result of measuring H NMR and GPC, １ H NMR indicated that the proportion of isoprene skeletons derived mainly from cyclic hydrocarbons was 80%, and GPC calculated that the component ratios of cyclic hydrocarbons (m = 4, 5, 6, 7, 8-15) were 37:16:9:7:19, respectively. A portion (1.37 g) of (Im) was dissolved in toluene, and the cyclic hydrocarbons were purified by Florisil chromatography (eluent: toluene / hexane = 1 / 3). As a result, a colorless liquid composition (Im) P2 containing cyclic hydrocarbons was obtained (0.97 g). １ H NMR indicated that the proportion of isoprene skeletons derived primarily from cyclic hydrocarbons was ≥95%, and GPC calculated that the component ratios of cyclic hydrocarbons (m = 4, 5, 6, 7, 8-15) were 36:19:10:9:21, respectively. (Im)P2 was further purified by recycle preparative GPC, and the individual components of cyclic hydrocarbons (m = 4, 5, 6, 7-15) ((Im)P2[m4], (Im)P2[m5], (Im)P2[m6], and (Im)P2[m7-15], respectively) were separated.

[0064] １ H and １３ ​Based on the results of C NMR measurements and other data, the main isomer of the cyclic hydrocarbon (Im)P2[m4] was thought to be a compound (1E,5Z,9Z,13Z)-1,5,9,13-tetramethylcyclohexadeca-1,5,9,13-triene) with one trans conformation and three cis conformations in the three-dimensional structure of the four double bonds (Chart 1).

[0065]

[0066] Its NMR data was as follows: 1 H NMR (CDCl3): δ(ppm) 1.60 (s, 3H, CH3), 1.66-1.74 (m, 9H, CH3), 1.90-2.20 (m, 16H, CH2), 5.05-5.22 (m, 4H, =CH) 13 C NMR (CDCl3): δ(ppm) 16.5 (C17), 22.6, 23.3, and 23.8 (C18, C19, C20), 24.9, 26.8, 27.6, and 28.0 (C3, C7, C11, C15), 31.4, 32.6, and 33.2 (C4, C8, C12), 40.4 (C16), 123.2, 125.0, 125.2, and 126.2 (C2, C6, C10, C14), 134.4, 135.4, 135.6, and 135.9 (C1, C5, C9, C13)

[0067] The GC / MS data of the major isomers of cyclic hydrocarbons (m = 4, 5, 6, and 7) were as follows: (Im)P2[m4] GC / MS (EI, 70 eV): m / z (%) 272 (M +, 12), 257 (12), 189 (10), 161 (18), 148 (11), 147 (21), 135 (15), 134 (25), 133 (26), 123 (12), 122 (19), 121 (68), 120 (20), 119 (56), 109 (31), 108 (26), 107 (63), 106 (14), 105 (34), 95 (32), 94 (40), 93 (95), 92 (21), 91 (28), 81 (58), 80 (21), 79 (47), 77 (20), 68 (100), 67 (85), 55 (35), 53 (38), 41 (42), 40 (10), 39 (15) (Im)P2[m5] GC / MS (EI, 70 eV): m / z (%) 340 (M + , 4.0), 161 (13), 147 (14), 135 (12), 134 (14), 133 (18), 123 (12), 122 (13), 121 (50), 120 (13), 119 (41), 109 (28), 108 (21), 107 (50), 106 (10), 105 (28), 95 (36), 94 (29), 93 (76), 92 (14), 91 (24), 81 (66), 80 (16), 79 (44), 77 (16), 68 (100), 67 (84), 55 (42), 53 (31), 41 (38) (Im)P2[m6] GC / MS (EI, 70 eV): m / z (%) 408 (M +, 3.0), 161 (13), 147 (13), 135 (13), 134 (13), 133 (15), 123 (12), 122 (11), 121 (46), 120 (11), 119 (36), 109 (30), 108 (18), 107 (48), 105 (26), 95 (40), 94 (26), 93 (74), 92 (12), 91 (21), 81 (77), 80 (14), 79 (41), 77 (13), 68 (100), 67 (75), 55 (42), 53 (22), 43 (11), 41 (30) (Im) P2 [m7] GC / MS (EI, 70 eV): m / z (%) 476 (M + , 2.4), 161 (13), 147 (13), 135 (15), 134 (12), 133 (15), 123 (15), 122 (12), 121 (49), 120 (10), 119 (34), 109 (34), 108 (18), 107 (50), 105 (25), 95 (47), 94 (25), 93 (80), 92 (11), 91 (20), 81 (90), 80 (14), 79 (40), 77 (10), 68 (100), 67 (68), 55 (44), 53 (16), 43 (11), 41 (24)

[0068] Example of Pyrolysis of Cyclic Hydrocarbons Example 20 A 5 mg / mL solution of composition (Il) (the product of Example 18) containing cyclic hydrocarbons was dissolved in toluene. A 5.0 μL portion of the solution was placed in a stainless steel container, and the solvent was evaporated. 25 μg of (Il) obtained after solvent evaporation was heated to 650°C using a pyrolyzer. The resulting pyrolysis products were analyzed by GC / MS and GC (Py-GC / MS and Py-GC). The results confirmed that isoprene, limonene, hydrocarbons with 1 to 4 carbon atoms, and hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene) were produced in yields of 20%, 3%, 5%, and 18%, respectively (see Table 3).

[0069] Examples 21 to 23 The decomposition reaction and analysis of the products were carried out in the same manner as in Example 20, but the reaction conditions (reaction temperature) were changed. The results are shown in Table 3.

[0070] (Example 24) A cyclic hydrocarbon-containing composition (II) (the product of Example 18) was dissolved in toluene to prepare a 5 mg / mL solution. A 5.0 μL portion of the solution was added to the catalyst La in a stainless steel container. ２ O ３ After the solvent was removed, the resulting La (II)-containing polymer was evaporated under reduced pressure. ２ O ３ was heated to 750°C using a pyrolyzer, and the resulting pyrolysis products were analyzed by GC / MS and GC (Py-GC / MS and Py-GC). As a result, it was confirmed that isoprene, limonene, hydrocarbons with 1 to 4 carbon atoms, and hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene) were produced in yields of 29%, 0%, 15%, and 27%, respectively (see Table 3).

[0071] Examples 25 to 27 The decomposition reaction and analysis of the products were carried out in the same manner as in Example 24, but with different reaction conditions (type of catalyst). The results are shown in Table 3.

[0072] Example 28 A 5 mg / mL solution of cyclic hydrocarbon-containing composition (Il)P1 (the product of Example 18 purified by silica gel chromatography) was dissolved in toluene. A 5.0 μL aliquot of this solution was placed in a stainless steel container, and the solvent was evaporated. 25 μg of (Il)P1 obtained after solvent evaporation was heated to 650°C using a pyrolyzer. The pyrolysis products were analyzed by GC / MS and GC (Py-GC / MS and Py-GC). The results confirmed that isoprene, limonene, hydrocarbons with 1 to 4 carbon atoms, and hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene) were produced in yields of 25%, 3%, 4%, and 18%, respectively (see Table 3).

[0073] Examples 29 to 31 The decomposition reaction and analysis of the products were carried out in the same manner as in Example 28, but the reaction conditions (reaction temperature) were changed. The results are shown in Table 3.

[0074] (Example 32) Composition (II) P1 containing cyclic hydrocarbons (the product of Example 18 purified by silica gel chromatography) was dissolved in toluene to prepare a 5 mg / mL solution. 5.0 μL of the solution was added to the catalyst La in a stainless steel container. ２ O ３ After the solvent was removed, the La 1000 sachets with 25 μg of (I1)P1 attached was obtained. ２ O ３ was heated to 650°C using a pyrolyzer, and the resulting pyrolysis products were analyzed by GC / MS and GC (Py-GC / MS and Py-GC). As a result, it was confirmed that isoprene, limonene, hydrocarbons with 1 to 4 carbon atoms, and hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene) were produced in yields of 36%, 0%, 24%, and 23%, respectively (see Table 3).

[0075] Examples 33 to 35 The decomposition reaction and analysis of the products were carried out in the same manner as in Example 32, but with different reaction conditions (type of catalyst). The results are shown in Table 3.

[0076] Example 36 A 5 mg / mL solution of composition (Il)P2 containing cyclic hydrocarbons (the product of Example 18 purified by Florisil chromatography) was dissolved in toluene. A 5.0 μL aliquot of this solution was placed in a stainless steel container, and the solvent was evaporated. 25 μg of (Il)P2 obtained after solvent evaporation was heated to 650°C using a pyrolyzer. The pyrolysis products were analyzed by GC / MS and GC (Py-GC / MS and Py-GC). The results confirmed that isoprene, limonene, hydrocarbons with 1 to 4 carbon atoms, and hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene) were produced in yields of 24%, 3%, 3%, and 19%, respectively (see Table 3).

[0077] Examples 37 to 39 The decomposition reaction and analysis of the products were carried out in the same manner as in Example 36, but the reaction conditions (reaction temperature) were changed. The results are shown in Table 3.

[0078] (Example 40) Composition (II) P2 containing cyclic hydrocarbons (the product of Example 18 purified by florisil chromatography) was dissolved in toluene to prepare a 5 mg / mL solution. 5.0 μL of the solution was added to the catalyst La in a stainless steel container. ２ O ３ After the solvent was removed, the La 1 mg solution was impregnated with 25 μg of (Il)P2. ２ O ３ was heated to 650°C using a pyrolyzer, and the resulting pyrolysis products were analyzed by GC / MS and GC (Py-GC / MS and Py-GC). As a result, it was confirmed that isoprene, limonene, hydrocarbons with 1 to 4 carbon atoms, and hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene) were produced in yields of 39%, 0%, 15%, and 34%, respectively (see Table 3).

[0079] Examples 41 to 43 The decomposition reaction and analysis of the products were carried out in the same manner as in Example 40, but with different reaction conditions (type of catalyst). The results are shown in Table 3.

[0080]

[0081] (Notes for Table 3) 1) In Examples 24-25, 32-33, and 40-41, a solution of a product containing cyclic hydrocarbons was impregnated onto a catalyst placed in a stainless steel container, and the solvent was distilled off under reduced pressure to carry out thermal decomposition. On the other hand, in Examples 26-27, 34-35, and 42-43, a solution of a product containing cyclic hydrocarbons was placed in a stainless steel container, the solvent was distilled off under reduced pressure, and then the catalyst was added to the stainless steel container to carry out thermal decomposition. 2) The cyclic hydrocarbons used were as follows: (Il): Composition containing cyclic hydrocarbons of Example 18 (Il) P1: Composition containing cyclic hydrocarbons after purification by silica gel column chromatography of Example 18 (Il) P2: Composition containing cyclic hydrocarbons after purification by Florisil column chromatography of Example 18 3) Details of the zeolite catalysts used are as follows: CP811-E75: CP811-E75 (H-beta zeolite, SiO) manufactured by Zeolyst ２ / Al ２ O ３= 75) CBV780: CBV780 (H-SDUSY type zeolite, SiO ２ / Al ２ O ３ = 81) 4) The yields of isoprene and limonene were calculated using the absolute calibration curve method. The yields of hydrocarbons with 1 to 5 carbon atoms and hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene) were calculated based on the area ratio of each hydrocarbon peak in gas chromatographic analysis. 5) Hydrocarbons with 1 to 4 carbon atoms. 6) Hydrocarbons with 5 to 10 carbon atoms (other than isoprene and limonene).

[0082] The present invention provides novel cyclic hydrocarbons having an isoprene skeleton, a method for producing the same, and uses thereof, and therefore the present invention is highly useful and has great industrial significance.

Claims

1. A cyclic hydrocarbon represented by the following general formula (I): [CH ２ -C(CH ３ )=CH-CH ２ ] ｍ (I) (In the formula, m is an integer of 4 or more and 15 or less, and has a structure in which both ends are bonded to each other.) 2. The cyclic hydrocarbon according to claim 1, wherein in the stereochemical structure of the double bonds of the general formula (I), at least one is in a trans configuration and the rest are in a cis configuration.

3. A composition comprising the cyclic hydrocarbon described in claim 1.

4. A method for producing the cyclic hydrocarbon or a composition containing the cyclic hydrocarbon described in claim 1 by reacting a metathesis catalyst with a polyisoprene represented by the following general formula (II) or a composition containing the polyisoprene. [CH ２ -C(CH ３ )=CH-CH ２ ] ｎ (II) (In the formula, n is an integer of 20 or more and 100,000 or less, the terminal groups are the same or different organic groups, and a part of the main chain may have a crosslinked structure.) 5. The method according to claim 4, wherein the composition containing polyisoprene is a composition containing carbon black or silica.

6. The method according to claim 4, wherein the metathesis catalyst is a metathesis catalyst containing ruthenium, molybdenum, tungsten, or titanium.

7. A method for producing hydrocarbons having 10 or less carbon atoms by pyrolyzing the cyclic hydrocarbons described in claim 1 or a composition containing the same.

8. A method for producing hydrocarbons having 10 or less carbon atoms, comprising pyrolyzing the cyclic hydrocarbons produced by the method according to claim 4 or a composition containing the same.

9. The method according to claim 7 or 8, wherein the hydrocarbon having 10 or less carbon atoms is isoprene.

10. The method according to claim 7 or 8, wherein the temperature range of the pyrolysis is 400 to 900°C.

11. The method according to claim 7 or 8, wherein the pyrolysis reaction is carried out in the presence of a catalyst.

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