Mixture of 3-hexene-1-ol isomers and preparation method thereof

Abstract

Described herein are compositions comprising 3-hexene-1-ol, and odor-imparting preparations comprising the compositions, and articles comprising the compositions or odor-imparting preparations. The compositions comprise trans-3-hexene-1-ol ranging from 67% to 82% by weight and cis-3-hexene-1-ol ranging from 18% to 33% by weight, wherein the total concentration of trans-3-hexene-1-ol and cis-3-hexene-1-ol is at least 97% by weight. A method for preparing a composition comprising 3-hexene-1-ol is also described herein, the method comprising: contacting 1-pentene with formaldehyde in the presence of a Lewis acid to obtain a crude mixture comprising 3-hexene-1-ol; and contacting a mixture comprising 3-hexene-1-ol with a base.

Description

[0001] Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 970,766, filed on February 6, 2020, the contents of which are incorporated herein by reference in their entirety.

[0003] Technical field and background technology of the present invention

[0004] In some embodiments of the present invention, the present invention relates to odor substances, more particularly but not exclusively, to a novel odor mixture of cis-3-hexen-1-ol and trans-3-hexen-1-ol, to preparations and products containing them, and to methods for preparing them.

[0005] Odorants are widely used in beverages, cosmetics, sanitary and hygienic goods, detergents, bath refreshing additives, medicines and agricultural chemicals, etc. Odorants are used to impart scent, odor, aroma or fragrance to products.

[0006] Fragrance (or aroma, odor or aroma) is produced by the combination of various components in a fragrance composition. Typically, fragrances are produced by blending odorous substances, optionally with carriers and other chemicals. These materials are blended to obtain the so-called "top note", "middle note" and "bottom note" components.

[0007] "Top notes" are the characteristics perceived immediately upon application. "Base notes" are the essence of a fragrance. This is usually composed of large, heavy molecules that evaporate slowly. Some base notes are perceived more than 24 hours after application. "Middle notes" are the characteristics perceived that bridge the top notes to the base notes. Middle notes usually appear after the top notes.

[0008] In recent years, green note fragrances have received particular attention. Agents that impart a fresh aroma of freshly cut grass are used, for example, in perfumery, candles, potpourri, bath and body products, melt-made soaps, cold process soaps, gel waxes, etc., and are also used to impart a grass scent to artificial grass or artificial turf.

[0009] The most recognized odorant imparting green notes is cis-3-hexen-1-ol, which is also known in the art as (Z)-3-hexen-1-ol, cis-3-hexenol, (Z)-3-hexenol, and also as "leaf alcohol". Other agents imparting green notes widely used in the industry include, for example, n-hexanal, n-hexanol, (E)-2-hexenal (trans-2-hexenal), (E)-2-hexen-1-ol (trans-2-hexen-1-ol) and (Z)-3-hexenal (cis-3-hexenal), and their ester derivatives.

[0010] Extraction of leaf alcohol and other grassy aroma-imparting substances from green plants and green leaves is generally costly to produce, with low production volumes, and is therefore commercially inefficient. In addition, the demand for green notes has grown to outstrip their supply from traditional natural sources such as peppermint (Mentha arvensis) oil and other vegetable oils. This has fueled research efforts to seek alternative ways to obtain these materials.

[0011] U.S. Patent Application Publication No. 2018 / 0037913 teaches a method for producing hexenol by using an enzymatic method.

[0012] Synthetic methods for preparing cis-3-hexen-1-ol and its derivatives have been developed in the past few decades. These methods generally involve the selective dehydrogenation of 3-hexyn-1-ol or conjugated enolates, and various starting materials can be used. Reference is made to, for example, RK Singh, E Singh, Handbook of Meat, Poultry and Seafood, 2007; J. Dorsky, Perfumes: Art, Science and Technology, 2012; Fragrance chemistry and technology, Zhao Yibin, Chemical Industry Press, 2007.

[0013] Chinese Patent Application Publication No. CN1244518 teaches a synthesis method using 1,3-pentadiene and 2-methyl-5,6-dihydrofuran through ring opening.

[0014] Chinese patent application publication No. CN101875599 teaches the reaction between 1-pentene and formaldehyde, formalin, paraformaldehyde or trioxane in the presence of a Lewis acid catalyst, followed by a post-processing procedure and distillation under reduced pressure to provide a mixture of geraniol and cis-3-hexene-1-ol. The mixture is then purified to obtain cis-3-hexene-1-ol. In one example, when paraformaldehyde and aluminum chloride are used, a mixture of geraniol and trans-3-hexene-1-ol is obtained.

[0015] Further background art includes WO 2006 / 116419 which describes the separation of E and Z isomers of enols, such as hexenol, or derivatives thereof, by continuously contacting an exchange medium with silver and / or copper ions with a feed stream comprising the E and Z isomers of the enol, or derivatives thereof. Summary of the invention

[0016] According to an aspect of some embodiments of the present invention, there is provided a method for preparing a composition comprising 3-hexen-1-ol, the method comprising:

[0017] contacting 1-pentene with formaldehyde in the presence of a Lewis acid to obtain a crude (first) mixture comprising 3-hexen-1-ol (also referred to herein as a crude first mixture); and

[0018] contacting the (crude first) mixture comprising 3-hexen-1-ol with a base,

[0019] A composition comprising 3-hexen-1-ol is thus obtained.

[0020] According to an aspect of some embodiments of the present invention, there is provided a composition comprising trans-3-hexen-1-ol in a concentration range of 67 wt % to 82 wt % and cis-3-hexen-1-ol in a concentration range of 18 wt % to 33 wt %, wherein the total concentration of the trans-3-hexen-1-ol and the cis-3-hexen-1-ol is at least 97 wt % (e.g., as determined by gas chromatography as described in the Examples section below).

[0021] According to an aspect of some embodiments of the present invention, there is provided a formulation for imparting odor, comprising a composition containing 3-hexen-1-ol, the composition being as described in any corresponding embodiment herein and any combination thereof.

[0022] According to an aspect of some embodiments of the present invention, there is provided a odor-imparting formulation comprising a composition containing 3-hexen-1-ol, the composition being obtainable by a method according to any corresponding embodiment described herein and any combination thereof.

[0023] According to an aspect of some embodiments of the present invention, there is provided an article-of-manufacturing comprising the odor-imparting formulation according to any corresponding embodiment described herein.

[0024] According to any of some embodiments of the present invention involving a method, the method comprises:

[0025] (a) contacting 1-pentene with formaldehyde in the presence of a Lewis acid, thereby obtaining a crude (first) mixture comprising 3-hexen-1-ol;

[0026] (b) distilling the crude (first) mixture to obtain a (first) mixture enriched in 3-hexen-1-ol (also referred to herein as the first mixture); and

[0027] (c) contacting the (first) mixture enriched in 3-hexen-1-ol with a base.

[0028] According to any of some embodiments of the present invention involving the method, the method further comprises separating the 3-hexen-1-ol from the mixture after contacting with the base, thereby obtaining a composition comprising 3-hexen-1-ol.

[0029] According to any of the embodiments of the present invention involving the isolation of 3-hexen-1-ol, the isolation of 3-hexen-1-ol comprises distillation (eg, as described in the Examples section below).

[0030] According to any of some embodiments of the present invention involving the method, the ratio of trans-3-hexen-1-ol to cis-3-hexen-1-ol in the crude (first) mixture is in the range of 7:3 to 8:2 (trans:cis).

[0031] According to any of the embodiments of the invention involving methods, contacting the (first) mixture with a base reduces the amount of at least one chlorinated tetrahydropyran by eliminating chlorine atoms (eg, eliminating HCl).

[0032] According to any of some of the embodiments of the present invention directed to reducing the amount of at least one chlorinated tetrahydropyran, the at least one chlorinated tetrahydropyran comprises 3-ethyl-4-chloro-tetrahydropyran.

[0033] According to any of the embodiments of the present invention directed to reducing the amount of the at least one chlorinated tetrahydropyran, after contacting with the base, the concentration of 3-ethyl-4-chloro-tetrahydropyran does not exceed 0.1 wt%, or does not exceed 0.05 wt%.

[0034] According to any of some of the embodiments of the present invention directed to reducing the amount of the at least one chlorinated tetrahydropyran, after contacting with the base, the total concentration of chlorinated tetrahydropyran does not exceed 0.1 weight percent.

[0035] According to any of some of the embodiments of the invention directed to methods, contacting 1-pentene with formaldehyde is accomplished by contacting 1-pentene with 1,3,5-trioxane (eg, as a precursor to formaldehyde).

[0036] According to any of some embodiments of the present invention involving methods, contacting 1-pentene with formaldehyde comprises adding a mixture containing 1-pentene and formaldehyde to the Lewis acid over a period of no more than two hours (within a period of no more than two hours). It should be noted that other lengths of time may also be used, for example, up to 24 hours, or 20 hours, or 18 hours, or 16 hours, or 12 hours, or 10 hours, or 8 hours, etc., depending on the reaction volume and the addition rate.

[0037] According to any of some embodiments of the present invention directed to the method, the Lewis acid is or comprises AlCl3.

[0038] According to any of some embodiments of the invention, the concentration of 3-hexen-1-ol in the composition is at least 97 weight percent.

[0039] According to any some embodiments of the invention, the composition comprises trans-3-hexen-1-ol at a concentration ranging from 67 wt% to 82 wt% and cis-3-hexen-1-ol at a concentration ranging from 18 wt% to 33 wt%.

[0040] According to any of some embodiments of the invention, the total concentration of 2-hexen-1-ol and 4-hexen-1-ol in the composition does not exceed 0.25 weight percent.

[0041] According to any of some embodiments of the invention, the concentration of 3-ethyl-4-chloro-tetrahydropyran in the composition does not exceed 0.05 weight percent.

[0042] According to any of some embodiments of the invention, the total concentration of chlorinated tetrahydropyrans in the composition does not exceed 0.1 weight percent.

[0043] According to any of some embodiments of the invention, the ratio of trans-3-hexen-1-ol to cis-3-hexen-1-ol in the composition ranges from 7:3 to 8:2 (trans:cis).

[0044] According to any of some embodiments of the invention, the composition further comprises 1-hexanol at a concentration of no more than 5 weight %, or no more than 4 weight %, or no more than 3 weight %, or no more than 2 weight %.

[0045] According to any of some embodiments of the invention, the composition further comprises 1-hexanol in a concentration of 0.01 wt%-5 wt%, or 0.01 wt%-4 wt%, or 0.01 wt%-3 wt%, or 0.01 wt%-2 wt%, or 0.1 wt%-5 wt%, or 0.1 wt%-4 wt%, or 0.1 wt%-3 wt%, or 0.1 wt%-2 wt%, or 1 wt%-5 wt%, or 1 wt% to 4 wt%, or 1 wt% to 3 wt%, or 1 wt% to 2 wt%, including any intermediate values ​​and subranges therebetween.

[0046] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as those generally understood by those of ordinary skill in the art to which the invention belongs. Methods and materials similar or equivalent to those described herein can be used to practice or test embodiments of the present invention, but exemplary methods and / or materials are described below. In the event of a conflict, the present patent specification including definitions shall prevail. In addition, materials, methods and examples are merely illustrative and are not intended to be necessarily restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Some embodiments of the present invention are described herein with reference to the accompanying drawings by way of example only. With specific reference now to the drawings in detail, it is emphasized that the details shown are by way of example and for the purpose of illustrative discussion of the embodiments of the present invention. In this regard, the description in conjunction with the drawings makes it clear to those skilled in the art how the embodiments of the present invention can be implemented.

[0049] In the attached picture:

[0050] Figure 1 A flow chart describing an exemplary method of preparing a product (composition) comprising 3-hexen-1-ol according to some embodiments of the present invention is presented.

[0051] Figure 2 A synthetic scheme is presented for an exemplary preparation of 3-hexen-1-ol from 1-pentene and trioxane, including elimination of chlorine (as HCl) from a chlorinated pyran derivative (chloropyran) byproduct, according to some embodiments of the present invention.

[0052] Figure 3 The gas chromatographic spectrum of the crude mixture (crude first mixture) obtained in the initial step of large-scale preparation of 3-hexene-1-ol according to some embodiments of the present invention is presented (x axis represents retention time in minutes; retention time). The peak at 9.173 is the peak of 1-hexanol. The peaks around 10.5 are the peaks of 4-hexene-1-ol and 2-hexene-1-ol.

[0053] Figure 4Presented are gas chromatographic spectra of a sample (crude second mixture) after removal of chlorine (as HCl) from a chlorinated pyran derivative byproduct in a crude (second) mixture of 3-hexene-1-ol according to some embodiments of the present invention (x-axis represents retention time in minutes). The peak near 4.8 minutes is the peak of the elimination product of the chlorinated pyran derivative (which is easily removed by subsequent distillation). The circle near 10 minutes shows the reduced amount of chlorinated pyran derivatives and 2-hexene-1-ol and 4-hexene-1-ol.

[0054] Description of specific embodiments of the present invention

[0055] Some embodiments of the present invention relate to odor substances, and more particularly, but not exclusively, to a novel odor mixture of cis-3-hexen-1-ol and trans-3-hexen-1-ol, to preparations and products containing the mixture, and to a method for preparing the mixture.

[0056] Before describing in detail at least one embodiment of the invention, it should be understood that the invention is not necessarily limited in its application to the details set forth in the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

[0057] As described above in the Background section, cis-3-hexen-1-ol and trans-3-hexen-1-ol are green note-imparting agents that are widely used in the industry. Therefore, there is a need for a synthetic method for preparing these compounds that is cost-effective and provides high purity compositions. Importantly, it is desirable to provide such an odor-imparting composition without byproducts that may mask or alter the odor of the odor-imparting agent.

[0058] The present inventors have found that a process for preparing 3-hexen-1-ol by reacting 1-pentene with formaldehyde can provide a combination of cis-3-hexen-1-ol and trans-3-hexen-1-ol in a ratio characterized by a particularly desirable odor by a relatively simple and inexpensive process.

[0059] The inventors have also discovered that the preparation of 3-hexen-1-ol by reacting 1-pentene with formaldehyde often produces significant levels of chlorinated pyran derivatives as by-products, which can negatively affect the odor of the composition and / or result in a product that is considered unsuitable for applications requiring high non-toxicity (e.g., involving ingestion) and cannot be separated from 3-hexen-1-ol without difficulty. This phenomenon presents a problem of choosing between reduced product quality and expensive separation technology.

[0060] After arduous experiments, the inventors have also found that the above problems can be solved by eliminating the chlorine atoms of the chlorinated pyran derivatives (such as eliminating hydrogen chloride) to obtain an elimination product that can be easily and effectively separated from 3-hexene-1-ol by simple techniques such as distillation. While simplifying the present invention to practice, the inventors have prepared a composition of 3-hexene-1-ol (using AlCl3 as Lewis acid) on a large scale without excessive labor, and the purity of the composition is high.

[0061] Therefore, embodiments of the present invention relate to a composition comprising cis-3-hexen-1-ol and / or trans-3-hexen-1-ol and having a low by-product content, a method for preparing such a composition, and an odor-imparting formulation and an article containing such a composition (or formulation). Embodiments of the present invention also relate to a novel composition comprising a mixture of trans-3-hexen-1-ol and cis-3-hexen-1-ol in a ratio of 6:4 to 9:1 (trans:cis), more specifically 67:33 to 82:18 (trans:cis).

[0062] Composition:

[0063] According to an aspect of some embodiments of the present invention, there is provided a composition comprising 67 to 82 wt% of trans-3-hexen-1-ol and 18 to 33 wt% of cis-3-hexen-1-ol of the composition.

[0064] As exemplified herein, compositions having the above concentrations of trans-3-hexen-1-ol and cis-3-hexen-1-ol exhibit particularly desirable odors and can be readily prepared without impurities or byproducts that have a negative impact on the product at levels. That is, the levels of impurities or byproducts in the composition that may affect the product (e.g., the odor properties of the product) are sufficiently low or absent that their impact is substantially eliminated.

[0065] According to an aspect of some embodiments of the present invention, a kind of composition comprising 3-hexene-1-ol (for example, according to any corresponding embodiment described herein, its concentration is at least 50 weight % of composition, or at least 60 weight % or at least 70 weight % or at least 80 weight % or at least 90 weight %) is provided, wherein the concentration of byproduct such as chlorinated pyran (for example, chlorinated tetrahydropyran) is low.In some such embodiments, the concentration of trans-3-hexene-1-ol in composition is the scope of 67 weight % to 82 weight %.In some such embodiments, the concentration of cis-3-hexene-1-ol in composition is the scope of 18 weight % to 33 weight %.In some such embodiments, the concentration of trans-3-hexene-1-ol is the scope of 67 weight % to 82 weight %, and the concentration of cis-3-hexene-1-ol is the scope of 18 weight % to 33 weight %.In some such embodiments, the concentration of trans-3-hexene-1-ol is the scope of 67 weight % to 82 weight %, and the concentration of cis-3-hexene-1-ol is the scope of 18 weight % to 33 weight %.

[0066] Herein, the terms "3-hexen-1-ol" and "3-hexenol" (which are used interchangeably herein) refer to trans-3-hexen-1-ol and / or cis-3-hexen-1-ol, including combinations thereof, unless otherwise specifically stated.

[0067] The 3-hexenol in the composition (according to any corresponding embodiment described herein) optionally comprises a combination of trans-3-hexen-1-ol and cis-3-hexen-1-ol, wherein the ratio of trans-3-hexen-1-ol to cis-3-hexen-1-ol in the composition is in the range of about 6:4 to about 9:1 (trans:cis). In some embodiments, the ratio of trans-3-hexen-1-ol to cis-3-hexen-1-ol in the composition is in the range of about 7:3 to about 8:2 (trans:cis).

[0068] As used herein, the terms "chlorinated pyran" and "chlorinated pyran derivatives" (which are used interchangeably herein) refer to any pyran, dihydropyran and / or tetrahydropyran substituted with one or more chlorine atoms and optionally with one or more additional substituents (e.g., alkyl).

[0069] As used herein, the terms "chlorinated tetrahydropyran" and "chlorinated tetrahydropyran derivatives" (which are used interchangeably herein) refer to tetrahydropyran substituted with one or more chlorine atoms, and optionally with one or more additional substituents (eg, alkyl groups).

[0070] Examples of substituents of pyran derivatives include, but are not limited to, hydroxyl (-OH), alkyl (e.g., C 1-4 -alkyl, such as methyl or ethyl), alkenyl (e.g., C 2-4Alkyl, alkenyl, such as vinyl) and alkoxy, wherein the alkyl, alkenyl and / or alkoxy may be unsubstituted or substituted (e.g., with hydroxy and / or chlorine). Ethyl is an exemplary substituent.

[0071] In any of the embodiments described herein, according to any of the aspects described herein, the total concentration of chlorinated pyrans in the composition does not exceed 0.5% by weight, optionally does not exceed 0.2% by weight, optionally does not exceed 0.1% by weight, optionally does not exceed 0.05% by weight, optionally does not exceed 0.02% by weight, optionally does not exceed 0.01% by weight, and optionally does not exceed 0.005% by weight.

[0072] In any of the embodiments described herein, according to any of the aspects described herein, the total concentration of chlorinated tetrahydropyran in the composition does not exceed 0.5% by weight, optionally does not exceed 0.2% by weight, optionally does not exceed 0.1% by weight, optionally does not exceed 0.05% by weight, optionally does not exceed 0.02% by weight, optionally does not exceed 0.01% by weight, and optionally does not exceed 0.005% by weight.

[0073] According to some embodiments of the present invention, 3-ethyl-4-chloro-tetrahydropyran is an exemplary chlorinated tetrahydropyran (see Figure 2 ).

[0074] Without being bound by any particular theory, it is believed that, at least according to some embodiments, the preparation of 3-hexenol is particularly susceptible to contamination with 3-ethyl-4-chloro-tetrahydropyran, and therefore compositions having low concentrations of 3-ethyl-4-chloro-tetrahydropyran (according to any corresponding embodiment described herein) are advantageous.

[0075] In any of the embodiments described herein, the composition has a low concentration of 3-ethyl-4-chloro-tetrahydropyran, for example, no more than 0.2 wt %, optionally no more than 0.1 wt %, optionally no more than 0.05 wt %, optionally no more than 0.02 wt %, optionally no more than 0.01 wt %, and optionally no more than 0.005 wt %.

[0076] Other examples of by-products, low concentrations of which are advantageous, are isomers of 3-hexenol, such as 4-hexen-1-ol and 2-hexen-1-ol.

[0077] In any of the embodiments described herein, according to any of the aspects described herein, the total concentration of 4-hexen-1-ol and 2-hexen-1-ol in the composition does not exceed 1 wt%, and optionally does not exceed 0.5 wt%.

[0078] In any of the embodiments described herein, the composition is substantially free of 4-hexen-1-ol and 2-hexen-1-ol.

[0079] As used herein, the term "substantially free" means that the concentration (e.g., the total concentration of 4-hexen-1-ol and 2-hexen-1-ol) does not exceed 0.25 wt%, optionally does not exceed 0.1 wt%, optionally does not exceed 0.05 wt%, optionally does not exceed 0.025 wt%, optionally does not exceed 0.01 wt%, optionally does not exceed 0.005 wt%, optionally does not exceed 0.0025 wt%, and optionally does not exceed 0.001 wt%.

[0080] In any of the corresponding embodiments described herein, the concentration of 3-hexenol (i.e., the total concentration of trans-3-hexene-1-ol and cis-3-hexene-1-ol) is at least 95% by weight of the composition, or at least 96% by weight, or at least 97% by weight. In some such embodiments, the concentration of 3-hexenol is at least 98% by weight of the composition. In some embodiments, the concentration of 3-hexenol is at least 99% by weight of the composition. In some embodiments, the concentration of 3-hexenol is at least 99.5% by weight of the composition. In some embodiments, the concentration of 3-hexenol is at least 99.8% by weight of the composition. In some embodiments, the concentration of 3-hexenol is at least 99.9% by weight of the composition.

[0081] In any of the corresponding embodiments described herein, when analyzed by gas chromatography, the composition has no peak at a retention time near 10.9 minutes or 11.3 minutes, and the analysis is preferably carried out under the following conditions (and exemplified in the Examples section): the injection volume is 1 μl, the column (e.g., a ZB-WAX column) uses a polyethylene glycol capillary column phase, a length of 30 m, an inner diameter of 0.25 mm, a film thickness of 0.25 μm, and a head pressure of 16.371 psi; the temperature program is from 50°C to 100°C at a rate of 5°C per minute, then from 100°C to 220°C at a rate of 10°C per minute, and then maintained at 220°C for 3 minutes (a total of 25 minutes); optionally using a flame ionization detector, the temperature is 260°C, the air flow rate is 360 ml / min, the H2 flow rate is 30 ml / min, and the He flow rate (makeup) is 24.8 ml / min.

[0082] In any of some of the corresponding embodiments described herein, the composition is characterized by a peak at around 9.5 minutes and / or a peak at around 9.95 minutes (e.g., associated with trans-3-hexen-1-ol and cis-3-hexen-1-ol, respectively), when analyzed by gas chromatography as described herein, and has no peak at a retention time of around 1.0 minutes or around 1.35 minutes that is longer than the peak at around 9.9 minutes, and / or has no peak at a retention time of around 1.45 minutes or around 1.8 minutes that is longer than the peak at around 9.5 minutes (when the analysis is preferably performed under the above conditions).

[0083] As used herein, "devoid of a peak" means the absence of a peak having an area of ​​at least 0.1% of the area of ​​the major product as indicated by the largest peak in a gas chromatograph (e.g., trans-3-hexen-1-ol or cis-3-hexen-1-ol).

[0084] In any of the embodiments described herein, the composition further comprises 1-hexanol at a concentration of 0.01 wt % to 5 wt %, or 0.01 wt % to 4 wt %, or 0.01 wt % to 3 wt %, or 0.01 wt % to 2 wt %, or 0.1 wt % to 5 wt %, or 0.1 wt % to 4 wt %, or 0.1 wt % to 3 wt %, or 0.1 wt % to 2 wt %, or 1 wt % to 5 wt %, or 1 wt % to 4 wt %, or 1 wt % to 3 wt %, or 1 wt % to 2 wt %, including any intermediate values ​​and subranges therebetween.

[0085] In any of the embodiments described herein, a composition as described in any corresponding embodiment herein is obtainable by a method of any embodiment described herein involving a method.

[0086] Herein, whenever weight % is shown, this is determined by means or methods known in the art. In some embodiments, weight % is determined by gas chromatography, such as quantitative gas chromatography, under conditions as described herein.

[0087] method:

[0088] According to an aspect of some embodiments of the present invention there is provided a method of preparing a composition comprising 3-hexen-1-ol.

[0089] According to some embodiments of the present invention, the composition is as described herein in any corresponding embodiment and any combination thereof.

[0090] According to an embodiment of the present invention, the method includes contacting 1-pentene with formaldehyde in the presence of a Lewis acid, thereby obtaining a crude mixture containing 3-hexen-1-ol (which is also referred to herein as a first mixture), and contacting the obtained mixture containing 3-hexen-1-ol (e.g., the first mixture) with a base.

[0091] Figure 1 Processes according to some embodiments of the present invention are depicted. As shown therein, the method starts at 10: contacting 1-pentene with formaldehyde in the presence of a Lewis acid (e.g., according to any of the corresponding embodiments described herein) to obtain a crude first mixture, and optionally followed by 20: distilling the crude first mixture (e.g., the mixture obtained in step 10) to obtain a first mixture enriched in 3-hexene-1-ol (e.g., a distilled crude first mixture according to any of the embodiments described herein). Then, proceed to 30: contacting the first mixture (e.g., the mixture obtained in step 20 and / or step 10) with a base (e.g., according to any of the embodiments described herein involving contact with a base) to obtain a second mixture (e.g., a crude second mixture), and optionally followed by 40: separating 3-hexene-1-ol from the mixture obtained after contacting with the base (the mixture obtained in step 30), for example, by distillation (e.g., according to any of the embodiments described herein involving separation of 3-hexene-1-ol). At step 50, a product (e.g., a composition comprising 3-hexene-1-ol according to any of the corresponding embodiments described herein) is obtained.

[0092] As exemplified herein, it is found that one or more chlorinated pyran derivatives (e.g., chlorinated tetrahydropyrans, such as 3-ethyl-4-chloro-tetrahydropyran) are often obtained as impurities, for example, at a concentration of more than 4% by weight of the crude mixture, and / or at a concentration of more than about 10% of the concentration of the obtained 3-hexenol, and that such impurities may be difficult to separate from the 3-hexenol by distillation, and it is found that contacting a mixture of 3-hexenol with a base (according to any corresponding embodiment described herein) can effectively convert the impurity into one or more compounds that are more easily separated from the 3-hexenol (e.g., by distillation) by eliminating chlorine atoms (so as to obtain molecules without chlorine atoms, for example, including a carbon-carbon double bond in place of each chlorine atom).

[0093] In some embodiments, the step of contacting 1-pentene with formaldehyde in the presence of a Lewis acid achieves a reaction of 1-pentene with formaldehyde to form 3-hexenol ( Figure 1 Step 10; Figure 2 ).

[0094] Lewis acids preferably act as catalysts for the reactions described herein. The Lewis acid may optionally be present in a catalytic amount (i.e., an amount significantly less than the amount of 1-pentene and formaldehyde). For example, the molar ratio of Lewis acid to 1-pentene and / or to formaldehyde may optionally be no more than 0.8, or no more than 0.7, or no more than 0.6, or no more than 0.5, or no more than 0.4, or no more than 0.3, or no more than 0.2, or no more than 0.1.

[0095] In any of the corresponding embodiments described herein, the molar ratio of Lewis acid to 1-pentene and / or to formaldehyde is at least 0.01 (e.g., 0.01 to 0.8), or at least 0.05 (e.g., 0.05 to 0.8), or at least 0.1 (e.g., 0.1 to 0.8), or at least 0.2 (e.g., 0.2 to 0.8), or at least 0.4 (e.g., 0.4 to 0.8).

[0096] " Lewis acid " as generally accepted in this area refers to a compound or substance as an electron pair acceptor. The example of Lewis acid includes but is not limited to compounds based on metals such as aluminum, boron, silicon, tin, titanium, zirconium, iron, copper and zinc, which are usually replaced by one or more electron withdrawing groups, such as one or more halogen atoms (such as fluorine, chlorine or bromine), such as BF , AlCl , TiCl , ZnCl and BCl . Except for one or more halogen atoms, such Lewis acid can be optionally replaced by one or more hydrocarbyl groups such as alkyl, cycloalkyl or aryl and / or replaced by one or more nitrile (cyano) substituents. The total number of substituents depends on the valence of the metal.

[0097] The Lewis acid may optionally be in liquid form (eg, in solution or suspension) and / or in solid form, such as granules, flakes, powder, and the like.

[0098] In any corresponding embodiments described herein, the Lewis acid comprises at least one chlorine atom, which can optionally serve as a chlorine source for producing the chlorinated pyran derivative.

[0099] AlCl (also known as aluminum chloride) is a non-limiting example of a (chlorine-containing) Lewis acid that can be used in any of the embodiments described herein involving Lewis acids. In some such embodiments, the AlCl is in particulate form. The AlCl can optionally be present in a catalytic amount (according to any of the corresponding embodiments described herein), for example, the molar ratio of AlCl to 1-pentene and / or to formaldehyde can optionally be no more than 0.8, no more than 0.7, or no more than 0.6, or no more than 0.5, or no more than 0.4, or no more than 0.3, or no more than 0.2, or no more than 0.1.

[0100] In any of the corresponding embodiments described herein, the molar ratio of AlCl3 to 1-pentene and / or to formaldehyde is at least 0.01 (e.g., 0.01 to 0.8), or at least 0.05 (e.g., 0.05 to 0.8), or at least 0.1 (e.g., 0.1 to 0.8), or at least 0.2 (e.g., 0.2 to 0.8), or at least 0.4 (e.g., 0.4 to 0.8). In an exemplary embodiment, the molar ratio of AlCl3 to 1-pentene and / or to formaldehyde is about 0.6.

[0101] Alternatively or additionally, the (chlorine-containing) Lewis acid may be another chloride of aluminum, for example, an alkylaluminum dichloride (i.e., RAlCl2, wherein R is an alkyl group) or a dialkylaluminum chloride (i.e., R'R"AlCl, wherein R' and R" are each an alkyl group). Examples of such Lewis acids include, but are not limited to, CH3AlCl2 and (CH3)2AlCl. Also contemplated are nitrile-substituted aluminum chlorides, wherein R' and / or R" are nitrile (cyano) groups.

[0102] Additional examples of (chlorine-containing) Lewis acids include, but are not limited to, boron chlorides (e.g., BCl3), iron chlorides (e.g., FeCl3), tin chlorides (e.g., SnCl4), and titanium chlorides (e.g., TiCl4), and their alkylated derivatives as described above.

[0103] The reaction can optionally be monitored by observing the color of the reaction mixture, which is preferably yellow in some embodiments. Brown color can indicate polymerization and heavy compound formation, which can result in lower yields.

[0104] As used herein, the term "formaldehyde" includes formaldehyde itself (i.e., H2C=O) as well as any compound known in the art that releases formaldehyde and / or is in equilibrium with formaldehyde; for example, oligomers of formaldehyde and / or polymers of formaldehyde (e.g., paraformaldehyde thereof) and / or hydrates (e.g., H2C(OH)2). The amounts of formaldehyde described herein are understood to include the molar equivalent of formaldehyde in embodiments using, for example, oligomers and / or polymers of formaldehyde.

[0105] In an exemplary embodiment, 1,3,5-trioxane (formaldehyde trimer, also referred to herein simply as "trioxane") is formaldehyde (optionally anhydrous trioxane) contacted with 1-pentene. One mole of trioxane is considered herein to be equivalent to three moles of formaldehyde.

[0106] In any of the embodiments described herein, 1-pentene is contacted with 1,3,5-trioxane in the presence of AlCl 3 (eg, under conditions and / or ratios according to any corresponding embodiment described herein).

[0107] Contacting 1-pentene with formaldehyde is optionally carried out at a controlled temperature, for example, at a temperature not exceeding 20°C, at a temperature not exceeding 10°C (for example, in the range of -5°C to 10°C), at a temperature not exceeding 5°C (for example, in the range of -5°C to 5°C), or at a temperature not exceeding 2°C (for example, in the range of -5°C to 2°C).

[0108] In order to maintain the reaction temperature within a controlled temperature range (e.g., according to any of the embodiments described herein), the contacting of 1-pentene and formaldehyde can be carried out gradually (e.g., gradually adding 1-pentene and / or formaldehyde to a Lewis acid, which can optionally initiate the reaction by acting as a catalyst), e.g., so that the exothermic nature of the reaction does not cause overheating of the reaction mixture. The exact rate suitable for such contacting can depend on, for example, the properties of the equipment and cooling system, and is well within the capabilities of those skilled in the art.

[0109] In addition, according to some embodiments, the contact time of 1-pentene and formaldehyde should not be too long. Excessive contact time may be associated with undesirable side reactions (e.g., polymerization). In any corresponding embodiments described herein, the contact time of 1-pentene and formaldehyde does not exceed 24 hours, or does not exceed 12 hours, or does not exceed 6 hours, or does not exceed 3 hours, or does not exceed 2 hours, or does not exceed 1 hour, or does not exceed 30 minutes.

[0110] In an exemplary embodiment, contacting 1-pentene with formaldehyde (according to any corresponding embodiment described herein) includes adding a mixture containing 1-pentene and formaldehyde to a Lewis acid (which can optionally initiate the reaction by acting as a catalyst) over the course of no more than two hours (e.g., 1.5 to 2 hours).

[0111] According to any embodiment described herein, polar solvent can be optionally used as solvent for 1-pentene, formaldehyde and / or Lewis acid.Preferably, polar solvent is aprotic polar solvent, such as acetonitrile, pyridine, ester (such as ethyl acetate, propylene carbonate), ether (such as tetrahydrofuran), ketone (such as acetone), amide (such as dimethylformamide, N-methyl-2-pyrrolidone), dimethyl sulfoxide and / or halogenated hydrocarbon.In some embodiments, solvent is halogenated hydrocarbon, such as chloroform, bromoform, methylene dichloride and similar solvents.Methylene dichloride is an exemplary solvent.

[0112] It should be understood that the terms "crude" and "crude mixture" as used herein are intended only to identify a mixture obtained at an intermediate stage of the process (eg, after contacting 1-pentene and formaldehyde), and are not intended to limit the composition of the mixture.

[0113] The 3-hexenol in the crude first mixture (according to any corresponding embodiment described herein) optionally comprises a combination of trans-3-hexene-1-ol and cis-3-hexene-1-ol. In some such embodiments, the ratio of trans-3-hexene-1-ol to cis-3-hexene-1-ol in the crude first mixture is in the range of 6:4 to 9:1 (trans: cis). In some embodiments, the ratio of trans-3-hexene-1-ol to cis-3-hexene-1-ol in the crude mixture is in the range of 7:3 to 8:2 (trans: cis). In some embodiments, the ratio of trans-3-hexene-1-ol in the crude mixture is substantially the same as the ratio of trans-3-hexene-1-ol to cis-3-hexene-1-ol in the composition obtained at the end of the method (i.e., the difference is no more than 50%, optionally no more than 20%, and optionally no more than 10%).

[0114] According to some embodiments, the method further comprises treating the crude first mixture to obtain a first mixture enriched in 3-hexene-1-ol (relative to the crude mixture), which is also referred to herein as an enriched first mixture, and which may optionally further comprise a chlorinated pyran (e.g., chlorinated tetrahydropyran) present in the crude mixture (e.g., according to any corresponding embodiment described herein). In some embodiments, the first mixture obtained is enriched in 3-hexene-1-ol and chlorinated pyran (relative to the crude mixture). Distillation of the crude mixture is an exemplary technique for obtaining a mixture enriched in 3-hexenol (enriched first mixture).

[0115] As exemplified herein, treating the crude first mixture (e.g., distilling the crude mixture) to increase the concentration of 3-hexenol therein (and optionally the concentration of the chlorinated pyran therein) can reduce the amount of isomers (e.g., 4-hexen-1-ol and 2-hexen-1-ol) formed upon contact with a base in a subsequent step.

[0116] As used herein, the term "enrichment" refers to any increase in concentration (eg, the concentration of 3-hexenol) relative to an initial concentration (eg, the concentration of a crude first mixture as described herein).

[0117] In any of some corresponding embodiments, the concentration of 3-hexenol in the mixture enriched with 3-hexenol (enriched first mixture) is at least 1.5 times the concentration of 3-hexenol in the crude mixture (i.e., 50% higher than the concentration of 3-hexenol in the crude mixture). In some embodiments, the concentration of 3-hexenol in the mixture enriched with 3-hexenol is at least 2 times (i.e., twice) the concentration of 3-hexenol in the crude mixture.

[0118] In any of some corresponding embodiments, the concentration of 3-hexenol in the mixture enriched with 3-hexenol is at least 50% by weight (and optionally at least 1.5 times or at least 2 times the concentration of 3-hexenol in the crude mixture). In some embodiments, the concentration of 3-hexenol in the mixture enriched with 3-hexenol is 60% by weight (and optionally at least 1.5 times or at least 2 times the concentration of 3-hexenol in the crude mixture). In some embodiments, the concentration of 3-hexenol in the mixture enriched with 3-hexenol is 70% by weight (and optionally at least 1.5 times or at least 2 times the concentration of 3-hexenol in the crude mixture). In some embodiments, the concentration of 3-hexenol in the mixture enriched with 3-hexenol is 80% by weight (and optionally at least 1.5 times or at least 2 times the concentration of 3-hexenol in the crude mixture). In some embodiments, the concentration of 3-hexenol in the 3-hexenol-enriched mixture is 90% by weight (and optionally at least 1.5 times or at least 2 times the concentration of 3-hexenol in the crude mixture).

[0119] The treatment of the crude first mixture is preferably carried out using any suitable equipment known in the art, such as acid-resistant equipment (eg, formed of glass and / or having a glass lining).

[0120] In any of the embodiments described herein, the method comprises:

[0121] (a) contacting 1-pentene with formaldehyde in the presence of a Lewis acid, thereby obtaining a crude (first) mixture comprising 3-hexen-1-ol (according to any corresponding embodiment described herein);

[0122] (b) distilling the crude mixture to obtain a (first) mixture enriched in 3-hexen-1-ol (according to any corresponding embodiment described herein), the enriched mixture optionally further comprising (and optionally enriched in) at least one chlorinated tetrahydropyran (e.g., 3-ethyl-4-chloro-tetrahydropyran); and

[0123] (c) contacting the (first) mixture enriched in 3-hexen-1-ol with a base, optionally reducing the amount of chlorinated tetrahydropyran (e.g., 3-ethyl-4-chloro-tetrahydropyran) by eliminating chlorine atoms (according to any corresponding embodiment described herein).

[0124] In any of the embodiments described herein, the base comprises a hydroxide salt (e.g., a metal hydroxide and / or a quaternary ammonium hydroxide), an amide salt (e.g., NaNH2, LiN(C2H5)2, and / or LiN(CH(CH3)2)2), a hydride salt (e.g., NaH) and / or a guanidine (e.g., HNC(NH2)2 or a substituted derivative thereof). In some such embodiments, the base is a metal hydroxide, optionally an alkali metal hydroxide, such as sodium hydroxide, potassium hydroxide, or lithium hydroxide. Potassium hydroxide is an exemplary base.

[0125] In some of any corresponding embodiments described herein, the total concentration of chlorinated pyrans remaining in the mixture after contacting with the base (according to any corresponding embodiment described herein) does not exceed 0.5 weight percent, optionally does not exceed 0.2 weight percent, optionally does not exceed 0.1 weight percent, optionally does not exceed 0.05 weight percent, optionally does not exceed 0.02 weight percent, optionally does not exceed 0.01 weight percent, and optionally does not exceed 0.005 weight percent.

[0126] In any of the embodiments described herein, after contacting with the base (according to any corresponding embodiment described herein), the total concentration of chlorinated tetrahydropyran remaining in the mixture does not exceed 0.5% by weight, optionally does not exceed 0.2% by weight, optionally does not exceed 0.1% by weight, optionally does not exceed 0.05% by weight, optionally does not exceed 0.02% by weight, optionally does not exceed 0.01% by weight, and optionally does not exceed 0.005% by weight.

[0127] In any of the embodiments described herein, after contacting with a base (according to any corresponding embodiment described herein), the concentration of 3-ethyl-4-chloro-tetrahydropyran remaining in the mixture is no more than 0.2% by weight, optionally no more than 0.1% by weight, optionally no more than 0.05% by weight, optionally no more than 0.02% by weight, optionally no more than 0.01% by weight, and optionally no more than 0.005% by weight.

[0128] Contacting the mixture comprising 3-hexenol (the crude first mixture or the enriched first mixture) with a base (according to any corresponding embodiment described herein) is optionally carried out at a temperature of at least 50°C (e.g., 50°C to 150°C), or at least 75°C (e.g., 75°C to 125°C), or at least 100°C.

[0129] In any of the embodiments described herein, the 3-hexenol mixture (the crude first mixture or the enriched first mixture) is gradually added to a composition comprising a base (e.g., further comprising a solvent such as polyethylene glycol), or vice versa. This gradual addition is optionally performed gradually over a period of at least 30 minutes, e.g., 30 minutes to 6 hours, or 1 hour to 3 hours, or 1 hour to 2 hours, or about 90 minutes.

[0130] According to any corresponding embodiment described herein, contacting the mixture comprising 3-hexenol (the crude first mixture or the enriched first mixture) with the base (the duration after all of the 3-hexenol mixture and the base have been combined) is optionally continued throughout the process for at least 2 hours (e.g., 2 to 24 hours) or at least 4 hours (e.g., 4 to 12 hours, or 5 to 7 hours).

[0131] According to any corresponding embodiment described herein, contacting a mixture comprising 3-hexenol (the crude first mixture or the enriched first mixture) with a base produces a mixture also referred to as a second mixture (eg, a second crude mixture).

[0132] In any of the embodiments described herein, the method further comprises separating 3-hexenol from other compounds in the (crude second) mixture (e.g., at least one product of eliminating a chlorine atom) after contacting with a base (e.g., according to any of the embodiments described herein). In some such embodiments, a composition according to any of the corresponding embodiments described herein is obtained after such separation.

[0133] As exemplified herein, separation of 3-hexenol from the product of elimination of chlorine atoms can be easily and conveniently achieved by distilling a mixture containing 3-hexenol and elimination product (crude second mixture, the mixture obtained when contacted with a base, according to any embodiment described herein).

[0134] The distillation can be performed as described in the Examples section below.

[0135] application:

[0136] As described herein, the composition according to any corresponding embodiment described herein comprises cis-3-hexen-1-ol and / or trans-3-hexen-1-ol. Such odor compounds obtainable by the method as described herein can be advantageously incorporated into odor-imparting (fragrance) preparations and / or articles, wherein it is beneficial to include such odor-imparting agents in the odor-imparting (fragrance) preparations and / or articles.

[0137] According to an aspect of some embodiments of the present invention, a kind of preparation (fragrant preparation) that imparts odor is provided, it is included in the composition as described herein in any corresponding embodiment.In some embodiments, the preparation that imparts odor comprises at least one other odor material (that is, in addition to the composition).Alternately or additionally, the preparation that imparts odor may optionally comprise at least one other component that is not an odor material, such as an acceptable carrier (for example, a carrier containing alcohol or water).Acceptable carriers may optionally be cosmetically acceptable, agriculturally acceptable, edible and / or suitable for detergents.

[0138] The term "odorant" as used herein and in the art describes a chemical substance or mixture of chemicals characterized by having an odor that is generally considered to be pleasant.

[0139] 3-hexenol can be used in a widely varying amount, depending on the specific application and the nature and amount of other odor components (if present) and / or the relative proportion of trans-3-hexene-1-ol and cis-3-hexene-1-ol. The proportion of 3-hexenol is generally 0.001% to 20% by weight of the total weight of the product or formulation containing 3-hexenol, but can also be as high as 50% by weight. The composition containing 3-hexenol described herein can be used in a widely varying amount (e.g., in a formulation and / or product that imparts odor as described herein), depending on the specific concentration of 3-hexenol in the composition, the ratio of trans-3-hexene-1-ol and cis-3-hexene-1-ol, and / or the nature and amount of other odor components (if present).

[0140] The scent-imparting formulation according to any embodiment described herein may be provided as a fragrance concentrate and / or as a fragrance formulation, which may be incorporated into an article as described herein.

[0141] According to an aspect of some embodiments of the present invention there is provided an article comprising a composition and / or a odor-imparting formulation as described herein.

[0142] In some embodiments, the article of manufacture includes a product to which an aroma-imparting agent has been added as a benefit.

[0143] In some embodiments, the articles include body care products, including bath / shower gels, hair conditioners, shampoos, liquid soaps, tablet soaps, cosmetics, and talcum powders; perfume products, particularly alcohol perfumes; cleaning products or compositions, such as liquid detergents; fabric care products, such as fabric softeners; and lifestyle products, such as pot pourri and incense.

[0144] Non-limiting examples of such articles include baby care, beauty care, fabric and home care, family care, feminine care, health care, snack and / or beverage products, and more specifically, but not limited to, fine fragrance products or formulations (e.g., perfumes, colognes, eau detoilettes, aftershave lotions, preshave lotions, face washes, water, tonics, and other fragrance-containing compositions for direct application to the skin), diapers, bibs, wipes; products and / or methods for treating hair (human, dog and / or cat), including bleaching, coloring, dyeing, conditioning, shampooing, styling preparations or products; deodorants and antiperspirants, personal cleansers, cosmetic and skin care products or preparations, including creams, lotions and other topically applied products, and shaving products; products and / or methods for treating fabrics, hard surfaces and any other surface in the fabric and home care fields, including air care, car care, dishwashing, fabric conditioning (including softening), laundry detergents, laundry additives and rinse additives and / or care, hard surface cleaning and / or treatment, and other cleaning compositions; and compositions for use with bath tissue, facial tissue, paper handkerchiefs and / or paper towels. products and / or methods involving toothpaste, tooth gel, tooth rinse, denture adhesive, and tooth whitener.

[0145] As used herein, the term "cleaning composition" includes cleaning agents, especially cleaning detergents, all-purpose cleaners in liquid, gel or paste form, liquid fine fabric detergents, hand dishwashing detergents or light dishwashing detergents, machine dishwashing detergents, including various tablet, granular, liquid and rinse aid types, cleaning and disinfecting agents, including antibacterial hand wash types, cleaning bars, mouthwashes, denture cleaners, tooth powders, car or carpet shampoos, bathroom cleaners, shampoos and hair rinses, shower gels and bubble baths and metal cleaners, as well as cleaning aids, such as bleach additives and "stain-stick" or pre-treatment types, substrate-loaded products, such as sheets with added desiccant, dry and moistened wipes and pads, nonwoven substrates and sponges, as well as sprays and mists.

[0146] As used herein, unless otherwise specified, the term "fabric care composition" includes fabric softening compositions, fabric enhancing compositions, fabric freshening compositions, and combinations thereof.

[0147] The 3-hexenol-containing compositions and / or odor-imparting formulations of embodiments of the present invention may be used in combination with one or more other odor-imparting (fragrance) agents.

[0148] The composition of the present embodiment can be used simply by directly mixing the composition or a fragrance preparation containing the composition with an article to which the composition is applied. Optionally, the composition or a fragrance preparation containing the composition can be embedded or embedded in a delivery system such as a polymer, capsule, microcapsule and nanocapsule, liposome, film former, absorbent such as carbon or zeolite, cyclic oligosaccharide and mixtures thereof, or can be chemically bonded to a substrate suitable for releasing the odorant upon application of an external stimulus such as light, enzyme, etc., and then applying the odorant to the article.

[0149] Therefore, embodiments of the present invention also include methods of making articles as described herein, which include incorporating an odorant or an odor-imparting formulation containing an odorant into the article, generally using conventional techniques and methods. By adding an odorant of embodiments of the present invention, the odor notes of the article can be improved, enhanced or changed.

[0150] It is expected that during the life of the patent maturing from this application, many related articles beneficially adding odorants will be developed, and the scope of the term "article" is intended to include all such a priori new technologies.

[0151] As used herein, the term "about" refers to ±10% or ±5%.

[0152] The terms "including", "comprising", "having" and their conjunctions mean "including but not limited to".

[0153] The term "consisting of" means "including and limited to."

[0154] The term "consisting essentially of" means that a composition, method, or structure may include additional ingredients, steps, and / or parts, but only applies if the additional ingredients, steps, and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method, or structure.

[0155] As used herein, the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

[0156] Throughout this article, various embodiments of the present invention may be presented in range format. It should be understood that the description of range format is only for convenience and brevity, and should not be interpreted as an unchangeable limitation on the scope of the present invention. Therefore, the description of the range should be considered to have specifically disclosed all possible sub-ranges and single values ​​within the range. For example, the description of a range such as 1 to 6 should be considered to have specifically disclosed sub-ranges, such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., and single values ​​within the range, such as 1, 2, 3, 4, 5 and 6. This applies to any width of the range.

[0157] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integer) within the indicated range. The phrases "range between a first indicated numeral and a second indicated numeral" and "range between a first indicated numeral and a second indicated numeral" are used interchangeably herein and are meant to include the first and second indicated numerals and all fractions and integers therebetween.

[0158] As used herein, the term "method" refers to manners, means, techniques, and procedures for accomplishing a given task, including but not limited to those manners, means, techniques, and procedures known to practitioners in the chemical arts or readily developed from known manners, means, techniques, and procedures.

[0159] In this article, the term "alkyl" describes a saturated aliphatic hydrocarbon including straight and branched groups. Preferably, the alkyl group has 1 to 20 carbon atoms. Whenever a numerical range such as "1-20" is expressed in this article, it means that the group (in this case, the alkyl group) may contain 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms. More preferably, the alkyl group is a medium-sized alkyl group with 1 to 10 carbon atoms. Most preferably, unless otherwise specified, the alkyl group is a low alkyl group with 1 to 4 carbon atoms (C (1-4) alkyl) or even 1 to 3 carbon atoms (C (1-3) alkyl). Exemplary alkyl groups include methyl, ethyl and propyl, preferably unsubstituted.

[0160] It should be understood that certain features of the invention described for clarity in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention described for brevity in the context of a single embodiment may also be provided individually, or in any suitable subcombination, or in any other described embodiment of the invention as appropriate. Certain features described in the context of various embodiments should not be considered essential features of those embodiments unless the embodiment cannot function without those elements.

[0161] Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the appended claims section find experimental support in the following examples. Example

[0162] Reference is now made to the following examples, which together with the above descriptions illustrate some embodiments of the invention in a non limiting fashion.

[0163] Example 1

[0164] Exemplary Methods for Preparing 3-Hexenol

[0165] According to some embodiments of the present invention, Figure 2 According to the exemplary synthesis scheme depicted in , 1-pentene is reacted with 1,3,5-trioxane (as a source of formaldehyde) to obtain a crude mixture containing 3-hexenol (crude first mixture), and the chlorinated byproduct is subsequently reacted with a base (e.g., potassium hydroxide).

[0166] In one exemplary method, the process of reacting 1-pentene with 1,3,5-trioxane to obtain crude 3-hexenol on a large scale is as follows.

[0167] Mixture 1 was prepared by charging 250 kg of trioxane (corresponding to 8.3 kmol of formaldehyde), 582 kg of 1-pentene (882 liters, 8.3 kmol), and 665 kg of dichloromethane (DCM) into a feed reactor and mixing.

[0168] Mixture 2 was prepared by charging 8116 kg of DCM into a reactor at 0°C, followed by 665 kg of AlCl3 (4.98 kmol).

[0169] After preparing mixture 2 in the reactor, it was cooled to -5°C. Mixture 1 was added dropwise during 1.5-2 hours, maintaining the temperature in the range of -5°C to 2°C.

[0170] Once the addition is complete, mix for 15 minutes and add the reaction mixture to 3588 kg of cooled 2% HCl until 15°C. After the addition is complete, the resulting mixture is stirred at 10°C for 15 minutes and then waited for phase separation for 15 minutes. The organic phase is then washed with 3046 kg of 10% NaHCO3 (pH = 8.5-9) at 10°C, then mixed for 15 minutes, and then waited for phase separation for 15 minutes. The DCM is then recovered with a short column at a temperature of 45°C and a pressure of 650-330 mbar, and 1008 kg of crude product (crude first mixture) is obtained, which contains 38% of 3-hexenol and 4%-6% of chloropyran derivatives (mainly 3-ethyl-4-chloro-tetrahydropyran), which is determined by gas chromatography. Figure 3As shown, the gas chromatography spectrum of the obtained crude product showed major peaks associated with trans-3-hexen-1-ol (at 9.481 minutes) and cis-3-hexen-1-ol (at 9.935 minutes), with smaller but significant peaks (at 10.933 minutes and 11.308 minutes) associated with the stereoisomers of 3-ethyl-4-chloro-tetrahydropyran.

[0171] Gas chromatography analysis was performed using a 7693 instrument (Agilent Technologies) with an injection volume of 1 μl, an inlet split ratio of 90:1, a temperature of 250°C, a ZB-WAX column (Restek) (polyethylene glycol capillary phase, 30 m long, 0.25 mm inner diameter, 0.25 μm film thickness, 16.371 psi head pressure), and a flame ionization detector (FID) (T = 260°C, air flow of 360 ml / min, H2 flow of 30 ml / min, He flow of 24.8 ml / min). The sample was diluted to 2% in dichloromethane. The temperature was increased from 50°C to 100°C at a rate of 5°C per minute, then from 100°C to 220°C at a rate of 10°C per minute, followed by heating at 220°C for 3 minutes (total 25 minutes).

[0172] The above procedure is repeated several times until a total of 3378 kg of crude product (crude first mixture) is obtained, which is then distilled to obtain 1362 kg of an enriched mixture (enriched first mixture) containing 85% 3-hexenol and 6%-8% chloropyran derivatives (mainly 3-ethyl-4-chloro-tetrahydropyran). A glass-filled column with 2-30, 2-20, 2-10 or 2-8 theoretical plates is used for distillation.

[0173] The enriched first mixture is then treated with KOH (potassium hydroxide) to dechlorinate the chloropyran derivatives to obtain a second mixture as described herein.

[0174] When dechlorination is performed without a previous distillation step to obtain an enriched mixture, a significant increase in 3-hexenol isomers, such as 2-hexenol and 4-hexenol, is observed. These isomers are difficult to separate from 3-hexenol by subsequent distillation and have an undesirable effect on the odor of the product.

[0175] 442kg PEG400 (1.1kmol) is loaded into the reactor, followed by 247kg KOH (3.9kmol), and the resulting mixture is heated to 100°C. Then 1362kg of the distillate of enriched 3-hexenol described above (85% 3-hexenol and 6%-8% chloropyran derivatives; enriched first mixture) is added dropwise over 1.5 hours while maintaining the temperature at 100°C. The reaction mixture is then stirred for 5-7 hours until the concentration of the chloropyran derivatives is no more than 0.05% by gas chromatography. After the reaction is complete, the mixture is cooled to room temperature and 741kg water is added, followed by heating the mixture to 60°C for 0.5 hours and phase separation. Then 680kg saturated NH4Cl is added to the organic phase at room temperature, and these phases are mixed and then separated. 1227 kg of crude product (crude second mixture) were obtained, which had 85% of 3-hexenol (trans: cis ratio of 80:20) and not more than 0.1% of chloropyran derivatives, as determined by gas chromatography. Figure 4 As shown, the gas chromatography spectrum of the obtained crude product (containing no chloropyran derivatives) showed major peaks associated with trans-3-hexen-1-ol (at 9.465 minutes) and cis-3-hexen-1-ol (at 9.921 minutes), while there was no significant peak associated with 3-ethyl-4-chloro-tetrahydropyran.

[0176] The crude product (crude second mixture) is then subjected to final distillation to obtain 1000 kg of 3-hexenol (trans: cis ratio of 80:20) with a purity of about 97% as determined by gas chromatography, and containing less than 0.1% of chloropyran derivatives and about 1%-3% of 1-hexanol. The final distillation is carried out using a column having 10-60 or 20-50 or 20-40 theoretical plates.

[0177] Example 2

[0178] Effects of chloropyran derivatives on the scent of 3-hexenol

[0179] A crude composition of 3-hexenol free of chloropyran derivatives prepared according to the procedure described in Example 1 was prepared and then distilled to obtain a 3-hexenol concentration of at least 97% by weight (trans:cis ratio of 72.5:27.5). The aroma of this composition was compared to the aroma of a similar 3-hexenol composition having 0.1% by weight or 0.3% by weight of 3-ethyl-4-chloro-tetrahydropyran.

[0180] 3-Hexenol without chlorinated pyran derivatives (>97%) exhibits a powerful and intensely green grassy odor.

[0181] 3-ethyl-4-chloro-tetrahydropyran alone exhibits a harsh, solvent-like odor. At a concentration of 0.3 wt % (in 3-hexenol), the irritation of 3-ethyl-4-chloro-tetrahydropyran is particularly prominent in the aroma of the mixture. At a concentration of 0.1 wt % (in 3-hexenol), the odor of 3-ethyl-4-chloro-tetrahydropyran is masked by the odor of 3-hexenol.

[0182] These results demonstrate that reducing the level of chloropyran derivatives in 3-hexenol compositions provides significant advantages.

[0183] In the presence of 1-hexanol at concentrations between 1% and 3%, the grassy odor of 3-hexenol (>97%) remained unmasked.

[0184] Although the present invention has been described in conjunction with specific embodiments, it is obvious that many substitutions, modifications and variations will be apparent to those skilled in the art. Therefore, the present invention is intended to include all such substitutions, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0185] All publications, patents and patent applications mentioned in this specification are incorporated by reference in their entirety into this specification, to the extent that each individual publication, patent or patent application is specifically and individually indicated as being incorporated by reference herein. In addition, the citation or identification of any reference in this application should not be construed as admitting that these references can serve as prior art of the present invention. Where section headings are used, they should not be construed as necessarily restrictive.

[0186] Additionally, any one or more priority documents of the present application are incorporated herein by reference in their entirety.

Claims

1. A method for preparing a composition comprising 3-hexen-1-ol, the method comprising: (a) contacting 1-pentene with formaldehyde in the presence of a Lewis acid to obtain a crude mixture comprising 3-hexen-1-ol; (b) distilling the crude mixture to obtain a mixture enriched in 3-hexen-1-ol; and (c) contacting the 3-hexen-1-ol enriched mixture with a base, Thus, the composition comprising 3-hexen-1-ol is obtained; wherein the method further comprises separating the 3-hexen-1-ol from the mixture after contacting with the base, thereby obtaining the composition comprising 3-hexen-1-ol; wherein the step of contacting the mixture with the base reduces the amount of at least one chlorinated tetrahydropyran by eliminating chlorine atoms; wherein the composition comprises trans-3-hexen-1-ol in a concentration range of 67 wt % to 82 wt % and cis-3-hexen-1-ol in a concentration range of 18 wt % to 33 wt %, wherein the total concentration of trans-3-hexen-1-ol and cis-3-hexen-1-ol is at least 95 wt %, wherein the total concentration of chlorinated tetrahydropyrans in the composition does not exceed 0.1 wt %.

2. The process of claim 1, wherein the step of separating the 3-hexen-1-ol comprises distillation.

3. The method of claim 1, wherein the concentration of 3-hexen-1-ol in the composition is at least 96% by weight.

4. The method of claim 1, wherein the concentration of 3-hexen-1-ol in the composition is at least 97% by weight.

5. The process according to claim 1, wherein the ratio of trans-3-hexen-1-ol to cis-3-hexen-1-ol in the crude mixture is 7:3 to 8:

2.

6. The method of claim 1, wherein the at least one chlorinated tetrahydropyran comprises 3-ethyl-4-chloro-tetrahydropyran.

7. The process according to claim 6, wherein after contacting with the base, the concentration of 3-ethyl-4-chloro-tetrahydropyran does not exceed 0.1 wt%.

8. The method of claim 6, wherein after contacting with the base, the concentration of 3-ethyl-4-chloro-tetrahydropyran does not exceed 0.05% by weight.

9. The process of claim 1, wherein after contacting with the base, the total concentration of chlorinated tetrahydropyrans does not exceed 0.1 wt%.

10. The method of claim 1, wherein the total concentration of 2-hexen-1-ol and 4-hexen-1-ol in the composition does not exceed 0.25% by weight.

11. The method of claim 1, wherein the step of contacting the 1-pentene with the formaldehyde is achieved by contacting the 1-pentene with 1,3,5-trioxane.

12. The method of claim 1, wherein the step of contacting the 1-pentene with the formaldehyde comprises adding a mixture containing the 1-pentene and the formaldehyde to the Lewis acid over a period of no more than two hours.

13. The method of claim 1, wherein the Lewis acid comprises AlCl3.

14. A composition comprising trans-3-hexen-1-ol in a concentration range of 67 wt% to 82 wt% and cis-3-hexen-1-ol in a concentration range of 18 wt% to 33 wt%, wherein the total concentration of trans-3-hexen-1-ol and cis-3-hexen-1-ol is at least 95 wt%, wherein the total concentration of chlorinated tetrahydropyrans in the composition does not exceed 0.1 wt%.

15. The composition of claim 14, wherein the total concentration of trans-3-hexen-1-ol and cis-3-hexen-1-ol is at least 96% by weight.

16. The composition of claim 14, wherein the total concentration of trans-3-hexen-1-ol and cis-3-hexen-1-ol is at least 97% by weight.

17. The composition of claim 14, wherein the total concentration of 2-hexen-1-ol and 4-hexen-1-ol in the composition does not exceed 0.25% by weight.

18. The composition of claim 14, wherein the chlorinated tetrahydropyran comprises 3-ethyl-4-chloro-tetrahydropyran and the concentration of 3-ethyl-4-chloro-tetrahydropyran in the composition does not exceed 0.05 wt%.

19. The composition of claim 14, wherein the ratio of trans-3-hexen-1-ol to cis-3-hexen-1-ol in the composition is 7:3 to 8:

2.

20. The composition of claim 14, further comprising 1-hexanol at a concentration of no more than 5% by weight.

21. The composition of claim 14, further comprising 1-hexanol at a concentration of no more than 4% by weight.

22. The composition of claim 14, further comprising 1-hexanol at a concentration of no more than 3% by weight.

23. The composition of claim 14, further comprising 1-hexanol at a concentration of no more than 2% by weight.

24. The composition of claim 14, wherein the concentration of 1-hexanol ranges from 1 wt% to 2 wt%.

25. An odor-imparting formulation comprising a composition containing 3-hexen-1-ol, the composition being obtained by the method of any one of claims 1 to 13.

26. A scent-imparting formulation comprising the composition of any one of claims 14 to 24.

27. An article of manufacture comprising the odor-imparting formulation of claim 25 or 26.

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