Bicyclic terpenoids as well as synthesis method and application thereof

Abstract

Compared with the prior art, the invention has the advantages that (E)-butyl-1, 3-diene-1-benzene reacts with a tetrayne compound in a solvent under the action of cesium carbonate, the preparation method is simple and efficient, the high-yield bicyclo-terpenoids can be obtained by controlling the reaction temperature, and the method is suitable for industrial production. And the structure is more complex and diversified. And the preparation method is mild, simple and green. The bicyclic terpenoids have high absorbance in ethanol at 320nm, which shows that the substance has good absorbance and can be well used for preparation of optical materials.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compound synthesis, and specifically relates to a bicyclic terpene compound and a synthesis method and application thereof. Background Art

[0002] Terpenoids are compounds and their derivatives derived from valeric acid and with isoprene units (C5 units) as the basic structural units of the molecular skeleton. These oxygen-containing derivatives can be alcohols, aldehydes, ketones, carboxylic acids, esters, etc. Simple cyclopentane compounds are generally liquids or low-melting solids. After glycoside formation, they are white crystals or amorphous hygroscopic powders. Such compounds are generally bitter and are one of the bitter ingredients in Chinese herbal medicines. There are chiral carbon atoms in the molecules, so they are optically active. In general, such compounds tend to be hydrophilic, and most of them are easily soluble in ethanol, acetone, and n-butanol, and are difficult to dissolve in lipophilic organic solvents such as chloroform, benzene, and petroleum ether.

[0003] Terpenoids are widely found in nature. Terpenoid components are found in higher plants, fungi, microorganisms, insects, and marine organisms. Macrocyclic terpenoids are composed of carbon rings with twelve or more members. They are a group of relatively unstable, structurally unique and diverse natural products. Most of the reported macrocyclic terpenoids are diterpenoids, including xanthoterpenes, casbanes, and leprosy papers. They are widely distributed in plants and marine organisms and are considered to be the biological genetic precursors of complex polycyclic terpenoids (such as taxanes and sulfanes). This type of compound is not only an important class of compounds in Chinese herbal medicines, many of which have been found to be active ingredients in Chinese herbal medicines, but also an important class of natural fragrances and an indispensable raw material for the cosmetics and food industries. Some compounds are also important industrial raw materials. For example, polyterpenoid rubber is a trans-linked isoprene long-chain compound and is an important raw material for the automotive and aircraft industries. The synthesis of macrocyclic terpenoids remains a challenge for chemists, and therefore, it is believed that macrocyclic terpenoids will play an increasingly important role in the future and provide very unique and promising opportunities for drug discovery with the development of synthetic methodologies, phenotypic screening and computational studies. Summary of the invention

[0004] The purpose of the present invention is to provide a bicyclic terpene compound and a synthesis method thereof. (E)-buta-1,3-diene-1-ylbenzene reacts with a tetraacetylene compound in a solvent under the action of cesium carbonate. The preparation method is simple and efficient. By controlling the reaction temperature, a high yield of bicyclic terpene compounds with more complex and diverse structures can be obtained. The preparation method is mild, simple and green.

[0005] Another object of the present invention is to provide an application of bicyclic terpenoid compounds for optical materials.

[0006] The specific technical solutions of the present invention are as follows:

[0007] A method for synthesizing a bicyclic terpene compound, specifically comprising:

[0008] (E)-buta-1,3-dien-1-ylbenzene, cesium carbonate and a tetrayne compound are heated in a solvent for reaction, and after the reaction is completed, the mixture is separated and purified to obtain a bicyclic terpene compound.

[0009] The molar ratio of the tetraacetylene compound, (E)-buta-1,3-diene-1-ylbenzene and cesium carbonate is 1:2:1;

[0010] The concentration of the tetraacetylene compound in the solvent is 0.25 mol / L.

[0011] The solvent is acetonitrile;

[0012] The structural formula of the (E)-buta-1,3-diene-1-ylbenzene is:

[0013] The heating reaction refers to reacting at 105-110° C. for 6 hours.

[0014] The separation and purification method comprises the following steps: extracting the crude product with a saturated sodium chloride aqueous solution and ethyl acetate, collecting the organic phase, performing decompression spin drying, wet column loading, and performing column chromatography separation and purification using ethyl acetate:petroleum ether in a volume ratio of 1:40 as an eluent to obtain a white solid product, namely, a bicyclic terpene compound.

[0015] The tetraacetylene compound has the structural formula E is COOR, R is a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group or an unsaturated hydrocarbon, preferably a methyl group; R1 is hydrogen, a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen, preferably hydrogen; R2 is hydrogen, a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen, preferably hydrogen.

[0016] Preferably, the tetraacetylene compound has the structural formula:

[0017] The tetraacetylene compound is prepared by the following steps:

[0018] 1) Add malonic acid ester and propargyl bromide to anhydrous acetonitrile in an ice-water bath, use sodium hydride as a base, react, and then purify and separate to obtain compound 1;

[0019] 2) Compound 1 prepared in step 1) is mixed with phenylacetyl bromide or 4-chlorophenylacetyl bromide in a CuCl anhydrous and oxygen-free catalytic system, an aqueous solution of n-butylamine and hydroxylamine hydrochloride are added, the mixture is stirred under ice bath for reaction, and a tetraacetylene compound is obtained after separation and purification.

[0020] In step 1), the molar ratio of sodium hydride, malonic acid ester, propargyl bromide and anhydrous acetonitrile is 4-5:1:2.1-2.4:20-23.

[0021] Preferably, the malonate in step 1) is selected from dimethyl malonate;

[0022] The reaction in step 1) is carried out in an ice-water bath at a temperature of 0-5°C and a reaction time of more than 8 hours; the preferred reaction time is 8.5 hours;

[0023] The structural formula of compound 1 in step 1) is Wherein E1 and E2 are the same, namely CO2R, R is a straight chain alkyl group, a branched chain alkyl group, a saturated hydrocarbon group, an unsaturated hydrocarbon group or an aromatic hydrocarbon group; preferably a methyl group;

[0024] The purification and separation in step 1) is specifically as follows: the product is washed with a saturated sodium chloride aqueous solution, extracted with ethyl acetate, dried under reduced pressure, and subjected to column chromatography using a mixed solvent of ethyl acetate: petroleum ether in a volume ratio of 1:80 to obtain the product, namely compound 1.

[0025] In step 2), the molar ratio of the compound 1: phenylethynyl bromide or 4-chlorophenylethynyl bromide: CuCl: hydroxylamine hydrochloride is 1: 2-2.5: 0.15-0.16: 0.07-0.08.

[0026] In step 2), the n-butylamine aqueous solution is used as a solvent, and its mass concentration is 30%.

[0027] In step 2), the dosage ratio of compound 1 to the aqueous solution of n-butylamine is 0.4-0.5 mol / L;

[0028] In step 2), the reaction is stirred in an ice bath for at least 12 hours;

[0029] In step 2), the preparation method of the phenylacetyl bromide is as follows: phenylacetylene and N-bromoacetyl succinimide are reacted in an acetone solvent under the catalysis of AgNO3 for 3 hours at room temperature, the crude product is washed with a saturated sodium chloride aqueous solution, and extracted with n-hexane to obtain phenylacetyl bromide; wherein the molar ratio of phenylacetylene: N-bromoacetyl succinimide and AgNO3 is 1:1-1.2:0.05.

[0030] In step 2), the separation and purification refers to: washing the product with a saturated sodium chloride solution, extracting with dichloromethane, drying under reduced pressure, and separating by column chromatography with a volume ratio of ethyl acetate: petroleum ether = 1:60-80 to obtain a solid product, i.e., a tetraacetylene compound.

[0031] The present invention provides a bicyclic terpene compound, which is prepared by the above-mentioned synthesis method. The structural formula of the bicyclic terpene compound is:

[0032] Wherein, E is CO2R; R is a straight-chain alkyl group, a branched-chain alkyl group or an unsaturated hydrocarbon with less than six carbon atoms;

[0033] R1 is hydrogen, a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group, or a halogen;

[0034] R2 is hydrogen, a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen.

[0035] Furthermore, R is preferably a methyl group; R1 is preferably a chlorine atom or an ethyl group; and R2 is preferably a chlorine atom or an ethyl group.

[0036] Furthermore, the bicyclic terpene compound has the structural formula:

[0037]

[0038] The invention provides an application of a bicyclic terpene compound for optical materials. The bicyclic terpene compound has a high absorbance at 320 nm in ethanol, indicating that the substance has good absorbance and can be well used in the preparation of optical materials.

[0039] The present invention uses tetraacetylene compounds and (E)-buta-1,3-diene-1-ylbenzene as raw materials, and the structural formula of (E)-buta-1,3-diene-1-ylbenzene is: In acetonitrile solvent, the reaction is carried out at 105-110°C for 6 hours. Under this condition, the tetrayne undergoes HDDA reaction to form a benzyne intermediate, which then forms a cation under the action of cesium carbonate. The cation undergoes a cycloaddition reaction with the compound formed by dimerization of (E)-buta-1,3-diene-1-ylbenzene. The mechanism diagram is shown in the figure below. Fig.10 As shown, tetrayne compounds undergo a [3+2] HDDA reaction at high temperature to generate benzyne compounds. Under the action of cesium carbonate, the benzyne compounds form cations, which capture the compounds formed by the dimerization of (E)-buta-1,3-diene-1-ylbenzene. In acetonitrile solvent, under heating conditions, they undergo a cycloaddition reaction to generate a diterpene compound transition state. In order to make the conjugated structure more stable, the diterpene compound obtains hydrogen anions, and finally forms a diterpene compound.

[0040] Compared with the prior art, the present invention reacts (E)-buta-1,3-diene-1-ylbenzene with a tetraacetylene compound in a solvent under the action of cesium carbonate. The preparation method is simple and efficient, and a high yield of bicyclic terpene compounds with more complex and diverse structures can be obtained by controlling the reaction temperature. The preparation method is mild, simple and green. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1It is the general structural formula of bicyclic terpenoid compounds;

[0042] Figure 2 is the structural formula of the bicyclic terpene compound prepared in Example 1;

[0043] Figure 3 is the structural formula of the bicyclic terpene compound prepared in Example 2;

[0044] Figure 4 The hydrogen nuclear magnetic resonance spectrum of the bicyclic terpenoid compound prepared in Example 1;

[0045] Figure 5 The carbon NMR spectrum of the bicyclic terpenoid compound prepared in Example 1;

[0046] Figure 6 The hydrogen nuclear magnetic resonance spectrum of the bicyclic terpenoid compound prepared in Example 2;

[0047] Figure 7 The carbon NMR spectrum of the bicyclic terpenoid compound prepared in Example 2

[0048] Figure 8 The preparation process equation of Example 1;

[0049] Fig. 9 The diagram is a mechanism for the preparation of tetrayne compounds;

[0050] Fig.10 The reaction mechanism diagram of bicyclic terpenoids;

[0051] Fig.11 This is the IUCr structure detection diagram of the bicyclic terpenoid compound prepared in Example 1;

[0052] Fig.12 It is the ultraviolet spectrum of the diterpenoid compound prepared in Example 2. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0055] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0056] Example 1

[0057] A bicyclic terpene compound, the structural formula of which is as follows:

[0058]

[0059] The preparation method of the bicyclic terpene compound comprises the following steps:

[0060] 1) Using 830 mmol of sodium hydride as a catalyst, 200 mmol of dimethyl malonate and 440 mmol of propargyl bromide were added to 210 mL of anhydrous acetonitrile, and the mixture was stirred mechanically in an ice-water bath at 0-5°C for 8 hours. The product was washed with a saturated sodium chloride aqueous solution, extracted with ethyl acetate, and dried under reduced pressure. Column chromatography was performed using a mixed solvent of ethyl acetate: petroleum ether in a volume ratio of 1:80 to obtain a product, namely compound 1, with the structural formula

[0061]

[0062] 2) Take 100mmol 4-chlorophenylacetylene and 120mmol N-bromoacetyl succinimide in a two-necked flask, add acetone solvent, and the solvent should cover the solid reactant by 0.5cm, add 5mmol AgNO3 catalyst, stir magnetically and react at room temperature for 3 hours, wash the crude product with saturated sodium chloride aqueous solution, extract with n-hexane to obtain 4-chlorophenylacetylene bromide.

[0063] 3) In a 500ml three-necked flask, 40mmol of compound 1 and 2.88mmol of hydroxylamine hydrochloride as a base are mixed in a 6mmolCuCl anhydrous and oxygen-free catalyst system (a vacuum device for evacuating and releasing argon is used, evacuating first and then releasing, and this is repeated 3 times), and then 100ml of a 30% by mass n-butylamine aqueous solution (63g water + 27g n-butylamine) is used as a solvent. First, half of the solvent is poured in, and then 90mmol of 4-chlorophenylacetylene bromide prepared in step 3) is poured in, and finally the remaining solvent is poured in. Under an ice bath, the reaction is stirred magnetically for 12 hours. The product is washed with a saturated sodium chloride solution and extracted with dichloromethane. The organic phase is collected, dried under reduced pressure, and chromatographed with a volume ratio of ethyl acetate: petroleum ether = 1:80 to obtain a white solid product, i.e., a tetraacetylene compound, with a structural formula of

[0064] 4) Under the condition of 110°C, 1.0mmol of the tetraacetylene compound prepared in step 3) was reacted with 1.0mmol of cesium carbonate and 2.0mmol of (E)-buta-1,3-diene-1-ylbenzene in 4mL of acetonitrile. After 6 hours, the reaction was stopped and the plate was spotted with TCL (volume ratio of petroleum ether: ethyl acetate = 8:1), and the spot analysis was performed under ultraviolet light. By comparing with the tetraacetylene compound spot, it was found that the tetraacetylene compound spot was basically reacted completely, and a new purple fluorescent spot was generated below the tetraacetylene compound spot. After that, the reaction solution was extracted with saturated sodium chloride aqueous solution and ethyl acetate, the organic phase was collected, dried under reduced pressure, wet loaded on a column, and separated by column chromatography with a volume ratio of ethyl acetate: petroleum ether = 1:40 to obtain a white solid product, i.e., a bicyclic terpene compound, and the column chromatography yield was about 75%.

[0065] Example 1 The product is a white powder. 1 H NMR, 13 C NMR was used to determine the results, and the results are as follows:

[0066] 1H NMR (400MHz, CDCl3) δ7.44-7.35(m,4H),7.25-7.23(m,1H),7.19(dd,J1=2.0Hz,J2=8.0Hz,1H),7.11(m,3H),7.06( m,4H),6.99(m,4H),6.92(d,J=7.2Hz,2H),5.77(dd,J1=9.2Hz,J2=14.8Hz,1H),5.61(m,1H),5.45(m,1H),5.31(J1= 10.0Hz,J2=14.8Hz,1H),4.00(m,2H),3.75(d,J=4.0Hz,6H),3.71(d,J=10.8Hz,1H),3.57(d,J=17.6Hz,1H),3.47(t ,J=10.0Hz,1H),3.09(m,1H),2.99(dd,J1=4.4Hz,J2=13.2Hz,1H),2.22(m,1H),1.67(dd,J1=12.8Hz,J2=24Hz,1H).

[0067] 13C NMR (101MHz, CDCl3) δ172.50,170.33,143.66,142.59,142.04,

[0068] 141.97,139.74,138.62,138.32,137.32,134.67,131.49 128.00 127.37

[0069] 123.68,118.65,95.94,87.85,64.28,57.53,55.66,53.31,52.82,

[0070] 49.56,39.10,36.39,35.72.

[0071] Example 2

[0072] A bicyclic terpene compound, the structural formula of which is as follows:

[0073]

[0074] The preparation method of the bicyclic terpene compound comprises the following steps:

[0075] 1) Using 830 mmol of sodium hydride as a catalyst, 200 mmol of dimethyl malonate and 440 mmol of propargyl bromide were added to 210 mL of anhydrous acetonitrile, and the mixture was stirred mechanically in an ice-water bath at 0-5°C for 8 hours. The product was washed with a saturated sodium chloride aqueous solution, extracted with ethyl acetate, and dried under reduced pressure. Column chromatography was performed using a mixed solvent of ethyl acetate: petroleum ether in a volume ratio of 1:80 to obtain a product, namely compound 1, with the structural formula

[0076]

[0077] 2) Take 100mmol 4-ethylphenylacetylene and 120mmol N-bromoacetyl succinimide in a two-necked flask, add acetone solvent, and the solvent covers the solid reactant by 0.5cm, add 5mmol AgNO3 catalyst, stir magnetically and react at room temperature for 3 hours, wash the crude product with saturated sodium chloride aqueous solution, extract with n-hexane to obtain 4-ethylphenylacetylene bromide.

[0078] 3) In a 500ml three-necked flask, 40mmol of compound 1 and 2.88mmol of hydroxylamine hydrochloride as a base are mixed in a 6mmolCuCl anhydrous and oxygen-free catalyst system (a vacuum device for evacuating and releasing argon is used, evacuating first and then releasing, and this is repeated 3 times), and then 100ml of a 30% by mass aqueous solution of n-butylamine (63g water + 27g n-butylamine) is used as a solvent. First, half of the solvent is poured in, and then 90mmol of 4-ethylphenylacetylene bromide prepared in step 3) is poured in, and finally the remaining solvent is poured in. Under an ice bath, the reaction is stirred magnetically for 12 hours. The product is washed with a saturated sodium chloride solution and extracted with dichloromethane. The organic phase is collected, dried under reduced pressure, and chromatographed with a volume ratio of ethyl acetate: petroleum ether = 1:80 to obtain a white solid product, i.e., a tetraacetylene compound, with a structural formula of

[0079] 4) Under the condition of 110°C, 1 mmol of the tetraacetylene compound prepared in step 3) was reacted with 1.0 mmol of cesium carbonate and 2.0 mmol of (E)-buta-1,3-diene-1-ylbenzene in 4 mL of acetonitrile. After 6 hours, the reaction was stopped and the plate was spotted with TCL (volume ratio of petroleum ether: ethyl acetate = 8:1), and the spot analysis was performed under ultraviolet light. By comparing with the tetraacetylene compound spot, it was found that the tetraacetylene compound spot was basically reacted completely, and a new purple fluorescent spot was generated below the tetraacetylene compound spot. After that, the reaction solution was extracted with saturated sodium chloride aqueous solution and ethyl acetate, the organic phase was collected, dried under reduced pressure, wet loaded on a column, and separated by column chromatography with a volume ratio of ethyl acetate: petroleum ether = 1:40 to obtain a white solid product, i.e., a bicyclic terpene compound, and the column chromatography yield was about 80%.

[0080] Example 2 (A vs. B) The product obtained is a white powder. The structure of the product was determined by 1H NMR and 13C NMR. The results are as follows:

[0081] 1H NMR (400MHz, CDCl3) δ7.34(s,2H),7.24(d,J=8.0Hz,3H),7.17(d,J=7.6Hz,1H),7.13-7.09(m,3H),7.05(t,J=7.2Hz,5H),7.02-6.96(m,3 H),6.92(d,J=7.6Hz,2H),5.77(dd,J1=9.2Hz,J2=15.2Hz,1H),5.65-5.57(m,1H),5.52-5.45(m,1H),5.31(dd,J1=10.0Hz,J2=15.2Hz,1H) ,4.02-3.98(m,2H),3.75(d,J=4.0Hz,6H),3.71(d,J=10.4Hz,1H),3.60(d,J=18.0Hz,1H),3.47(t,J=10.4Hz,1H),3.08(d,J=7.2Hz,2H), 2.72(q,J=7.6Hz,2H), 2.61(q,J=7.6Hz,2H), 2.20(d,J=12.4Hz,1H), 1.69(q,J=12.0Hz,1H), 1.31(t,J=7.6Hz,3H), 1.20(t,J=7.6Hz,3H).

[0082] 13C NMR (101MHz, CDCl3) δ172.52,170.37,144.53,143.71,143.07,142.65,142.03,141.82,137.05,130.67,128.34,127.46,126. 07,120.98,118.99,96.12,87.45,64.30,57.52,55.67,53.27,52.79,49.57,39.11,36.40,35.76,28.99,28.90,15.96,15.57.

[0083] UV absorbance test, the product of Example 2, the concentration in ethanol is 29.6 μg / ml, and has a higher absorbance at 320 nm, such as Fig.12 As shown, it indicates that the substance has good absorbance and can be well used in the preparation of optical materials.

[0084] 1.0 mmol of the tetraacetylene compound prepared in Example 1 was mixed with 1.0 mmol of cesium carbonate and 2.0 mmol of 1,1,4,4-tetraphenyl-1,3-butadiene in 4 mL of acetonitrile. After 6 hours of reaction, the reaction was stopped and the plate was spotted with TCL (volume ratio of petroleum ether: ethyl acetate = 8:1), and the spot analysis was performed under ultraviolet light. By comparing with the spots of tetraacetylene compounds and 1,1,4,4-tetraphenyl-1,3-butadiene (raw material spots), it was found that the two raw materials were basically unreacted and no obvious new fluorescent spots were generated.

[0085] The description of the above embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for synthesizing a bicyclic terpene compound, characterized in that: The synthesis method is specifically: (E)-buta-1,3-dien-1-ylbenzene, cesium carbonate and a tetrayne compound are heated in a solvent for reaction, and after the reaction is completed, the mixture is separated and purified to obtain a bicyclic terpene compound.

2. The synthesis method according to claim 1, characterized in that The molar ratio of the tetrayne compound, (E)-buta-1,3-diene-1-ylbenzene and cesium carbonate is 1:2:

1.

3. The synthesis method according to claim 1 or 2, characterized in that The concentration of the tetraacetylene compound in the solvent is 0.25 mol / L.

4. The synthesis method according to claim 1 or 3, characterized in that The solvent is acetonitrile.

5. The synthesis method according to claim 1 or 3, characterized in that: The heating reaction refers to reacting at 105-110° C. for 6 hours.

6. The synthesis method according to claim 1, characterized in that The separation and purification method comprises the following steps: extracting the crude product with a saturated sodium chloride aqueous solution and ethyl acetate, collecting the organic phase, performing decompression spin drying, wet column loading, and performing column chromatography separation and purification using ethyl acetate:petroleum ether in a volume ratio of 1:40 as an eluent to obtain a white solid product, namely, a bicyclic terpene compound.

7. The synthesis method according to claim 1 or 2, characterized in that: The tetraacetylene compound has the structural formula E is COOR, R is a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group or an unsaturated hydrocarbon; R1 is hydrogen, a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen; R2 is hydrogen, a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen.

8. A bicyclic terpene compound synthesized by the synthesis method according to any one of claims 1 to 7, characterized in that: The structural formula of the bicyclic terpenoid compound is: E is CO2R; R is a straight-chain alkyl group, a branched-chain alkyl group or an unsaturated hydrocarbon with less than six carbon atoms; R1 is hydrogen, a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group, or a halogen; R2 is hydrogen, a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen.

9. The bicyclic terpene compound according to claim 8, characterized in that The bicyclic terpene compound structural formula is:

10. Use of the bicyclic terpene compound according to claim 8 or 9, characterized in that: For optical materials.

Images