JPH11100339A - Production of tricyclodecanedimethanol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing tricyclodecanedimethanol from dicyclopendadiene, easy in handling operations such as the recovery, extractive separation, purification, and the like of the tricyclodecanedimethanol and enabling the production of the tricyclodecanedimethanol in high productivity and at a low cost. SOLUTION: This method for producing tricyclodecanedimethanol comprises hydroformylating dicyclopentadiene in the presence of a catalyst comprising a rhodium compound and a phosphite having an electronic parameter ψ of 2080-2090 cm<-1> and a steric parameter θ of 135-190 degree in a lower alcohol and subsequently hydrogenating the obtained solution containing the tricyclodecanedicarbaldehyde in the presence of a hydrogenation catalyst. Therein, a tertiary amine compound is contained in the hydroformylation reaction solution in an amount of 50-1500 mole times that of the rhodium metal in the reaction solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing tricyclodecane dimethanol by obtaining tricyclodecane dicarbaldehyde by a hydroformylation reaction of dicyclopentadiene, and reducing it with hydrogen. Tricyclodecane dimethanol is useful, for example, as a raw material for unsaturated polyester resins and acrylic resins.

[0002]

2. Description of the Prior Art Tricyclodecane dicarbaldehyde is obtained by hydroformylation of dicyclopentadiene,
It is known that tricyclodecane dimethanol can be obtained by further reducing this with hydrogen. For example, British Patent No. 750,144 discloses hydrocarbon solvents,
Disclosed is a method for obtaining tricyclodecane dimethanol from dicyclopentadiene by performing a hydroformylation reaction in the presence of a catalyst comprising a polymerization inhibitor, a stabilizer, and a cobalt compound, and then performing hydrogen reduction with a nickel catalyst. Have been. Also, British Patent No. 1170226
In the specification, hydroformylation is performed using a catalyst containing rhodium in a hydrocarbon solvent at a temperature of 80 ° C. or higher and a pressure of 30 atm or higher, and then the reaction temperature and pressure are increased to perform hydrogen reduction. And a method for obtaining tricyclodecane dimethanol from dicyclopentadiene in one pot. JP-B-63-31450 discloses a process for producing tricyclodecane dimethanol by performing hydroformylation and hydrogen reduction using a cobalt-phosphine catalyst in a hydrocarbon solvent, followed by extraction and separation with water and a polar solvent. Is disclosed.
Japanese Patent No. 4526 describes a method in which after performing hydroformylation and hydrogen reduction in a hydrocarbon solvent, a tricyclodecane dimethanol layer is separated, and the solvent containing the separated catalyst is recycled and reused. Also, U.S. Pat.
No. 0241 discloses an alcohol used as a solvent in a hydroformylation reaction for the purpose of converting a dialdehyde produced in a hydroformylation reaction of dicyclopentadiene into a stable acetal derivative at a high temperature and suppressing a side reaction from the dialdehyde. A method for producing tricyclodecane dimethanol by obtaining tricyclodecane dicarbaldehyde using a system solvent and further performing hydrogen reduction is described.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have intensively studied a method for producing tricyclodecane dimethanol. As a result, it was recognized that the conventional technology for producing tricyclodecane dimethanol using a hydrocarbon-based solvent has the following problems. That is, a layer of only tricyclodecane dimethanol or a layer of tricyclodecane dimethanol containing some hydrocarbon-based solvent is obtained as a product, but the target tricyclodecane dimethanol is a compound having an extremely high viscosity, Since handling operations such as recovery, extraction separation, and purification become difficult, there is a problem that the isolation yield of tricyclodecane dimethanol decreases. In addition, these known reactions have a problem that the production cost of tricyclodecane dimethanol is high because the concentration of the rhodium catalyst used in the hydroformylation reaction process is high.

On the other hand, the method for producing tricyclodecane dimethanol using an alcoholic solvent described in US Pat. No. 2,880,241 has the following problems. The dialdehyde acetalized in the presence of an alcoholic solvent is stable at high temperatures, but the hydrogen reduction reaction is significantly slowed down, so the productivity of the process for producing tricyclodecane dimethanol from tricyclodecane dicarbaldehyde is increased. It will drop significantly. In addition, if the acetal compound remains without hydrogen reduction, the selectivity of tricyclodecane dimethanol decreases, and the productivity decreases.In addition, the boiling point of the acetal compound and the boiling point of tricyclodecane dimethanol decrease. There is also a problem that the separation by distillation is difficult because there is no difference.

Accordingly, an object of the present invention is to provide a method for producing tricyclodecane dimethanol by a hydroformylation reaction of dicyclopentadiene and hydrogen reduction.
Easy handling such as purification, high productivity,
Another object of the present invention is to provide an inexpensive manufacturing method.

[0006]

According to the present invention, dicyclopentadiene is prepared by mixing a rhodium compound and an electrochromic parameter ν in a lower alcohol-based solvent.
Hydroformylation in the presence of a phosphite catalyst of 80 to 2090 cm ^-1 and a steric parameter θ of 135 to 190 degrees, and the resulting solution containing tricyclodecane dicarbaldehyde is treated in the presence of a hydrogenation catalyst. In the method for producing tricyclodecane dimethanol by hydrogen reduction, the presence of the tertiary amine compound in the hydroformylation reaction solution in an amount of 50 to 1500 mole times the amount of rhodium metal in the reaction solution. The above object can be achieved by providing a method for producing tricyclodecane dimethanol, which is a feature.

BEST MODE FOR CARRYING OUT THE INVENTION

The lower alcohol solvent used in the present invention is preferably an alcohol having 6 or less carbon atoms which is easily available industrially and dissolves tricyclodecane dimethanol. Specific examples include methanol, ethanol,
n-propyl alcohol, isopropyl alcohol, n
-Butyl alcohol, sec-butyl alcohol, t-
Examples thereof include butyl alcohol, n-pentanol, n-hexanol and cyclohexanol, and more preferably isopropyl alcohol. These alcohol solvents may be used alone or in combination of two or more.

In the present invention, the reaction can be carried out using only these lower alcohol solvents, but other organic solvents inert to the reaction may coexist. Specific examples of such a solvent include aromatic hydrocarbons such as benzene, toluene, and xylene;
Higher alcohols such as octyl alcohol, decanol and dodecanol; ethers such as diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran and dioxane; esters such as methyl acetate, dioctyl phthalate and dimethyl adipate. These solvents can be used alone or in combination of two or more kinds in combination with the above-mentioned lower alcohol solvents.

According to the present invention, the proportion of the lower alcohol solvent and the other solvent is not limited as long as the tricyclodecane dimethanol does not undergo phase separation. Further, according to the present invention, the use amount of the lower alcohol solvent and the other solvent is a total amount of the solvent, and may be set in a range not exceeding 50% by volume based on the reaction solution taken out from the reactor. Preferably, it is possible to industrially advantageously produce tricyclodecane dimethanol without lowering the productivity.

In the present invention, a phosphite which forms a catalyst for a hydroformylation reaction with a rhodium compound is represented by a general formula P (-OR ¹ ) (-OR ² ) (-OR ³ ) (wherein R ¹ , R ² And R ³ each represent an aryl group or an alkyl group which may be substituted.), And its electronic parameter ν is 2080 to
2090 cm ^-1 and the steric parameter θ
A known phosphite having a temperature of 135 to 190 degrees can be used. Here, the electronic parameter ν and the stelicy parameter θ are values defined by CA Tolman, Chemical Reviews, Vol. 77, pp. 313, 1977, and the electronic parameter ν is phosphorus. The parameter for evaluating the electronic effect when the compound forms a metal complex is calculated based on the carbonyl contraction wave of the Ni carbonyl complex, and the steric parameter θ is a parameter for evaluating the steric effect of the phosphorus compound. Is calculated from the cone angle of the molecular model. Specific examples of R ¹ , R ² and R ³ include methyl, ethyl, isopropyl, n-butyl, t
Aryl groups such as phenyl group and naphthyl group which may be substituted with -butyl group, methoxy group and the like; aliphatic alkyl groups such as methyl group, ethyl group, isopropyl group, n-butyl group and t-butyl group; methyl Group, ethyl group,
Examples thereof include an alicyclic alkyl group such as a cyclopentyl group and a cyclohexyl group which may be substituted with a lower alkyl group such as an isopropyl group, an n-butyl group, and a t-butyl group. Specific examples of suitable phosphites include tris (2-t-butylphenyl) phosphite, tris (3
-Methyl-6-t-butylphenyl) phosphite, tris (3-methoxy-6-t-butylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, di (2-t -Butylphenyl) t-butyl phosphite and the like, but are not limited to only these phosphites. These phosphites may be used alone or in combination of two or more.

The phosphite used in the present invention may be used in an excess of 15 to 400 mol times, preferably 100 to 200 mol times, of rhodium metal in the hydroformylation reaction solution. If present, tricyclodecane dicarbaldehyde can be obtained at a satisfactory hydroformylation rate.

The rhodium metal-phosphite complex catalyst used in the present invention can be formed by methods known in the art. That is, rhodium dicarbonyl acetylacetonate, Rh ₂ O ₃ , Rh ₄ (CO) ₁₂ , Rh ₆
A catalyst precursor such as (CO) ₁₆ and Rh (NO ₃ ) ₃ is introduced into the reaction mixture together with a phosphite ligand to form a rhodium metal hydride carbonyl phosphite complex having catalytic activity in the reaction vessel. Alternatively, a rhodium metal hydride carbonyl phosphite catalyst may be prepared in advance and introduced into the reaction vessel. In a preferred embodiment of the present invention, rhodium dicarbonyl acetyl settonate is used as a rhodium precursor and reacted with phosphite in the presence of a solvent and then introduced into the reactor together with excess free phosphite into the catalyst. An active rhodium-phosphite complex catalyst can be used. In any event, it is sufficient for the purposes of the present invention that the active rhodium-phosphite catalyst be present in the reaction mixture under the presence of carbon monoxide and hydrogen used in the hydroformylation reaction.

The preferred amount of rhodium in the hydroformylation catalyst used in the present invention is in the range of 0.01 to 0.08 mg atom per liter of reaction solution as rhodium metal at a satisfactory hydroformylation rate and tricyclodemethyl. Candicarbaldehyde can be obtained. That is, in the present invention, the amount of the expensive rhodium catalyst used is smaller than the concentration of the rhodium catalyst used in the above-mentioned known hydroformylation process, so that the catalyst cost can be reduced.

Examples of the tertiary amine compound used in the present invention include aliphatic tertiary amines such as trimethylamine, triethylamine, tri-n-butylamine, tri-n-octylamine and triethanolamine;
Examples include aromatic tertiary amines such as N, N-dimethylaniline, N, N-diethylaniline, and triphenylamine, or heterocyclic tertiary amine compounds such as pyridine and quinoline. Of these, aliphatic tertiary amines having 3 to 24 carbon atoms are preferred, and triethylamine is more preferred.

The amount of the tertiary amine compound to be used is in the range of 50 to 1500 mole times, preferably 100 to 150 times the amount of rhodium metal as the catalyst in the hydroformylation reaction.
It is in the range of 1000 molar times. By causing the tertiary amine compound within this range to be present in the hydroformylation reaction solution, the acetalization of the lower alcohol-based solvent and tricyclodecane dicarbaldehyde can be sufficiently suppressed, and the acetal selectivity can be reduced. it can. If the amount of the tertiary amine compound used is less than 50 times the amount of rhodium metal, the effect of suppressing acetalization of the lower alcohol solvent and tricyclodecane dicarbaldehyde is insufficient. On the other hand, if the amount is more than 1500 mole times, the basic unit of the tertiary amine compound becomes large, which is economically disadvantageous.

The temperature and pressure conditions for carrying out the hydroformylation reaction of the present invention are from 40 ° C. to 160 ° C.
C., preferably a reaction temperature of 80-140.degree.
Reaction pressure of ~ 150 atm. When the temperature is lower than 40 ° C., the reaction of hydroformylation is slow, and when the temperature is higher than 160 ° C., side reactions from dicyclopentadiene and hydroformylation reaction products in the reaction solution proceed to deteriorate the reaction results. When the pressure is lower than 10 atm, the reaction of hydroformylation is slow, and when the pressure is higher than 150 atm, a high-pressure reactor is used, so that the equipment cost increases. The molar ratio of hydrogen to carbon monoxide in the hydrogen / carbon monoxide mixed gas used for the reaction can be selected from the range of 0.2 to 5.0 as the composition of the introduced gas. If the hydrogen / carbon monoxide mixed gas is out of this range, the reaction activity of the hydroformylation reaction or the aldehyde selectivity decreases.

The hydroformylation reaction in the present invention comprises
It can be carried out in a batch system or a continuous feed system using a known reactor. It is known that in the reaction solution of the hydroformylation reaction, cyclopentadiene generated by thermal decomposition of the raw material dicyclopentadiene decreases the activity of the hydroformylation catalyst. Since it is more advantageous in suppressing the formation of pentadiene, a preferred method of hydroformylation is to supply dicyclopentadiene to the reactor by a continuous feed.

As the catalyst for reducing hydrogen of tricyclodecane dicarbaldehyde used in the present invention, a known metal catalyst having a hydrogen reducing ability, such as nickel, cobalt, rhodium or palladium, can be used. These metal catalysts can be used in the form of a simple metal, a metal oxide, an inorganic substance supported, or a metal complex, and added to the reaction solution after hydroformylation of dicyclopentadiene. Among these hydrogenation catalysts, Raney nickel catalysts are preferable from the viewpoint of the rate of the hydrogen reduction reaction and the separation of the catalyst after the reaction. Suitable amounts of these catalysts vary depending on the type of catalyst, reaction temperature, and desired reaction rate. For example, in Raney nickel catalyst, 0.2 to 10% by weight, preferably 1 to 10% by weight, based on tricyclodecane dicarbaldehyde. ~
By using 5% by weight, tricyclodencanedimethanol can be produced with industrially advantageous productivity. As a method for supplying these catalysts to the reaction solution after dicyclopentadiene is hydroformylated, the above-mentioned lower alcohol-based solvent or other organic inert to the reaction may be added directly to the hydroformylation reaction solution. The solvent may be added as a homogeneous solution or a slurry solution.

The conditions for the reaction temperature and pressure for producing tricyclodencan dimethanol by hydrogen-reducing the hydroformylation reaction solution containing tricyclodecane dicarbaldehyde are from 40 to 200 ° C., preferably from 80 to 1 ° C.
The reaction temperature is 50 ° C. and the reaction pressure is 100 atm or less. When the temperature is lower than 40 ° C., the hydrogen reduction reaction is slow, and when the temperature is higher than 200 ° C., the side reaction from the target tricyclodecane dimethanol proceeds to deteriorate the reaction results.
On the other hand, when the pressure is higher than 100 atm, the cost of the apparatus increases because a high-pressure reactor is used.

The hydrogen reduction of the hydroformylation reaction solution containing tricyclodecane dicarbaldehyde in the present invention is carried out by
It can be carried out in a batch system or a continuous feed system using a known reactor.

The thus obtained crude reaction solution containing tricyclodecane dimethanol and a lower alcohol solvent can be recovered and purified by an easy handling operation without increasing the viscosity even after cooling. As a method for purifying this tricyclodecane dimethanol, general means, for example, adsorption of a catalyst from the reaction mixture as necessary,
After removal by operations such as extraction and filtration, tricyclodecane dimethanol can be separated and purified from the crude product obtained by distilling off the solvent by operations such as thin film evaporation and distillation.

[0022]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 1.9 mg of rhodium dicarbonyl acetylacetonate, 0.96 g of tris (2,4-di-t-butylphenyl) phosphite, and 0.96 g of rhodium were placed in a 500 ml stainless steel autoclave with a stirrer and purged with nitrogen. Of 100
0.075 g of a molar amount of triethylamine, 25 ml of isopropyl alcohol and 23 ml of toluene were added,
After replacing with a mixed gas of hydrogen / carbon monoxide (1/1), stirring was started, the temperature was adjusted to 120 ° C., and the pressure was adjusted to 90 atm with the same mixed gas. A mixture of 176.4 g of dicyclopentadiene and 30 ml of isopropyl alcohol was supplied to this reactor over 4 hours while maintaining the temperature and pressure. The rhodium concentration in terms of rhodium metal based on the total charged liquid amount is 0.03 mg atom / liter. After the reaction was further continued for 4 hours under the same conditions, cooling and depressurization were performed, and 319.1 g of the reaction solution was taken out and stored under a nitrogen atmosphere. As a result of gas chromatographic analysis, the conversion of dicyclopentadiene was 100%, and the yield of tricyclodecanedicarbaldehyde was 93%. Next, 1.0 g of Raney nickel catalyst was placed in a stainless steel autoclave with a stirrer having a capacity of 100 ml and purged with nitrogen.
Then, 10 ml of isopropyl alcohol and 10 ml of isopropyl alcohol were added, and after replacement with hydrogen gas, stirring was started. The temperature was adjusted to 110 ° C., and the pressure of hydrogen gas was adjusted to 8 atm. While maintaining the temperature and the pressure, 35.0 g of the above hydroformylation reaction solution containing tricyclodecane dicarbaldehyde was supplied to this reactor over 4 hours. From gas chromatography analysis,
The conversion of tricyclodecane dicarbaldehyde in the reaction solution immediately after the end of the supply was 94%. After the reaction was further continued for 2 hours under the same conditions, cooling and pressure release were performed, and 42.0 g of the reaction solution was taken out. As a result of gas chromatography analysis, the conversion of tricyclodecane dicarbaldehyde was 100%, the yield of tricyclodecane dimethanol based on dicyclopentadiene was 91%, and tricyclodecane dicarbaldehyde was completely reduced by hydrogen. The remaining acetal was 0.4% based on tricyclodecane dimethanol.

Example 2 In the preparation of tricyclodecane dicarbaldehyde in Example 1, the amount of triethylamine was changed to 1 relative to rhodium.
Instead of using 0.075 g of a molar amount of 00,
Dicyclopentadiene 17 was prepared in the same manner as in Example 1 except that the amount was changed to 0.75 g, which was 1000 times the amount of rhodium.
A hydroformylation reaction was carried out using 6.4 g, and hydrogen reduction of tricyclodecane dicarbaldehyde was carried out in the same manner as in Example 1. As a result of gas chromatographic analysis of the crude reaction solution, the conversion of tricyclodecane dicarbaldehyde was 100%, the yield of tricyclodecane dimethanol based on dicyclopentadiene was 91%, and tricyclodecane dicarbaldehyde was completely obtained. The acetal compound remaining without hydrogen reduction was 0.4% based on tricyclodecanedimethanol.

Comparative Example 1 Dicyclopentadiene 176.4 was prepared in the same manner as in Example 1 except that triethylamine was not added when producing tricyclodecane dicarbaldehyde.
g, and then a hydrogen reduction reaction using the crude hydroformylation reaction solution was performed, and the reaction was further performed for 2 hours after supplying the hydroformylation reaction solution to the reactor in Example 1, except that the reaction time was changed to 6 hours. Carried out hydrogen reduction of tricyclodecane dicarbaldehyde in the same manner as in Example 1. As a result of gas chromatographic analysis of this crude reaction solution, the conversion of tricyclodecane dicarbaldehyde was 100%, the yield of tricyclodecane dimethanol based on dicyclopentadiene was 89%, and the tricyclodecane dicarbaldehyde was completely converted. The acetal compound remaining without hydrogen reduction was 2.0% based on tricyclodecane dimethanol.

Comparative Example 2 In the preparation of tricyclodecane dicarbaldehyde in Example 1, the amount of triethylamine was changed to 1 relative to that of rhodium.
Instead of using 0.075 g of a molar amount of 00,
Dicyclopentadiene 17 was prepared in the same manner as in Example 1 except that the amount was 0.023 g, which was 30 times the amount of rhodium.
A hydroformylation reaction was carried out using 6.4 g, and a further 2 hours after supplying the hydroformylation reaction solution to the reactor in the hydrogen reduction reaction using the crude hydroformylation reaction solution in Example 1, the reaction time was 6 hours. The hydrogen reduction of tricyclodecane dicarbaldehyde was carried out in the same manner as in Example 1 except that the reaction was carried out. As a result of gas chromatographic analysis of this crude reaction solution, the conversion of tricyclodecane dicarbaldehyde was 100%, the yield of tricyclodecane dimethanol based on dicyclopentadiene was 89%, and the tricyclodecane dicarbaldehyde was completely converted. The remaining acetal form without hydrogen reduction was 1.9% based on tricyclodecanedimethanol.

Comparative Example 3 In the preparation of tricyclodecane dicarbaldehyde in Example 1, the amount of triethylamine was changed to 1 relative to rhodium.
Instead of using 0.075 g of a molar amount of 00,
Dicyclopentadiene 17 was prepared in the same manner as in Example 1 except that the amount was changed to 1.50 g, which is 2000 times the amount of rhodium.
A hydroformylation reaction was carried out using 6.4 g, and hydrogen reduction of tricyclodecane dicarbaldehyde was carried out in the same manner as in Example 1. As a result of gas chromatographic analysis of the crude reaction solution, the conversion of tricyclodecane dicarbaldehyde was 100%, the yield of tricyclodecane dimethanol based on dicyclopentadiene was 90%, and tricyclodecane dicarbaldehyde was completely converted. The acetal compound remaining without hydrogen reduction was 0.4% based on tricyclodecanedimethanol.

Comparative Example 4 The amounts of rhodium carbonyl acetylacetonate and tris (2,4-di-t-butylphenyl) phosphite used in Example 1 were 0.32 mg and 0.16 mg, respectively.
g, and the hydroformylation reaction was carried out using 176.4 g of dicyclopentadiene in the same manner as in Example 1 except that the amount of triethylamine was 0.013 g, which was 100 times the amount of rhodium. At this time, the rhodium concentration in terms of rhodium metal based on the total charged liquid amount is 0.005 mg atom / liter. As a result of gas chromatography analysis of the crude reaction solution after the hydroformylation reaction was continued for 4 hours,
The conversion of dicyclopentadiene was 35% and the yield of tricyclodecanedicarbaldehyde was 11%.

Comparative Example 5 The amounts of rhodium carbonyl acetylacetonate and tris (2,4-di-t-butylphenyl) phosphite used in Example 1 were 6.4 mg and 3.20 g, respectively.
A hydroformylation reaction was carried out using 176.4 g of dicyclopentadiene in the same manner as in Example 1, except that the amount of triethylamine was changed to 0.252 g, which was 100 times the amount of rhodium. At this time, the rhodium concentration in terms of rhodium metal based on the total amount of the charged liquid was 0.1 mg atom / liter. Further, hydrogen reduction of tricyclodecane dicarbaldehyde was performed in the same manner as in Example 1. As a result of gas chromatographic analysis of the crude reaction solution, the conversion of tricyclodecane dicarbaldehyde was 100%, the yield of tricyclodecane dimethanol based on dicyclopentadiene was 86%, and the tricyclodecane dicarbaldehyde was complete. The acetal compound remaining without hydrogen reduction was 0.5% based on tricyclodecanedimethanol.

[0030]

According to the present invention, when producing tricyclodecane dimethanol from dicyclopentadiene, handling operations such as recovery, extraction separation and purification of tricyclodecane dimethanol are easy and productivity is high. And an inexpensive manufacturing method is provided.

Claims (4)

[Claims] 1. A catalyst comprising a rhodium compound and a phosphite having an electrochromic parameter ν of 2080 to 2090 cm ⁻¹ and a steric parameter θ of 135 to 190 ° in a lower alcohol solvent containing dicyclopentadiene. Hydroformylation below,
In a method for producing tricyclodecane dimethanol by hydrogen reduction of a solution containing the obtained tricyclodecane dicarbaldehyde in the presence of a hydrogenation catalyst, a tertiary amine compound is added to a hydroformylation reaction solution. A process for producing tricyclodecane dimethanol, which is present in an amount of 50 to 1500 times the amount of rhodium metal in the reaction solution. 2. The process for producing tricyclodecane dimethanol according to claim 1, wherein the lower alcohol solvent is an aliphatic alcohol having 1 to 6 carbon atoms. 3. The rhodium compound concentration in the hydroformylation reaction solution is 0.01 to 0.08 as rhodium metal.
3. The process for producing tricyclodecane dimethanol according to claim 1, wherein the amount is mg atom / liter. 4. A tertiary amine compound having 3 to 24 carbon atoms.
An aliphatic tertiary amine of any one of claims 1 to 3.
3. The method for producing tricyclodecane dimethanol according to the above item.