Antitumor ascorbate esters

Abstract

The present invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof or a stereoisomer thereof or a mixture of stereoisomers thereof, wherein n is an integer from 0 to 10; R1 is a divalent radical selected from CH2, O, NH and S; and R2 is (C3-C 15 ) alkyl. The present invention also provides a pharmaceutical composition comprising the compound of formula (I), and the use of the compound and the pharmaceutical composition as a medicament, more specifically for the treatment or prevention of tumor diseases such as pancreatic cancer.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of European Patent Application EP20382804, filed on September 14, 2020. Technical field

[0003] The present invention relates to the field of anti-tumor compounds, in particular to anti-tumor ascorbyl esters and anti-tumor compositions comprising said esters. The present invention also relates to the use of said esters and said compositions for prophylactic or therapeutic cancer treatment. Background art

[0004] Cancer is a group of diseases involving abnormal cell growth and the potential to invade or spread to other parts of the body. Currently, there are few effective options for treating many common cancer types. The course of treatment for a given individual depends on the diagnosis, the stage of disease development, and factors such as the patient's age, sex, and overall health. The most conventional options for cancer treatment are surgery, radiotherapy, and chemotherapy. Each of these therapies has varying degrees of efficacy and is accompanied by a variety of side effects. These side effects, combined with the well-documented multi-drug resistance of traditional chemotherapy, have created an urgent need for new anti-cancer drugs or treatment methods.

[0005] One particularly deadly type of cancer is pancreatic cancer. This type of cancer is a malignant growth of the pancreas, mainly occurring in the cells of the pancreatic duct. This disease is the ninth most common form of cancer, but it is the fourth and fifth leading cause of cancer death in men and women, respectively. Pancreatic cancer is almost always fatal, with a five-year survival rate of less than 3%.

[0006] The current treatment procedures available for pancreatic cancer have not led to a cure nor to a significantly improved survival time. Surgical resection is the only way to provide a chance of survival. However, due to the large tumor burden, only 10% to 25% of patients are candidates for "curative resection". For those patients who undergo surgical treatment, the five-year survival rate remains very low, averaging only about 10%. Therefore, pancreatic cancer is one of the cancer types with a high need for the development of effective therapies.

[0007] A molecule that has long been considered a potential anti-cancer agent is ascorbic acid, also known as vitamin C. However, ascorbic acid exhibits very limited bioavailability and has been shown to induce acute oxalate nephropathy in some cases.

[0008] To overcome the limitations of using ascorbic acid as an anti-cancer molecule, many new ascorbic acid derivatives have been developed in recent years by modifying its hydroxyl groups. Among them, fatty acid esters of ascorbic acid, ascorbyl palmitate, and ascorbyl stearate have attracted considerable interest as anti-cancer compounds due to their lipophilic nature and ease of crossing cell membranes and the blood-brain barrier.

[0009] However, ascorbyl fatty acid esters have several drawbacks due to their high hydrophobicity. Specifically, they are difficult to handle and dissolve to obtain a homogeneous liquid composition that can be easily administered to a patient.

[0010] Accordingly, despite efforts made so far, there remains a need for compounds that have high anti-tumor activity and are easy to handle and administer to a patient. SUMMARY OF THE INVENTION

[0011] The inventors have developed various different ascorbyl esters that are capable of inhibiting cancer cell growth.

[0012] Surprisingly, the inventors have found that the esterification of ascorbic acid with a group comprising a cycloalkyl group attached to an alkyl carbon chain gives rise to compounds that exhibit potent cancer-inhibiting activity and have a moderate hydrophobicity.

[0013] As shown in the examples below, the compounds provided herein effectively inhibit the growth of cancer cells from various different sources, such as pancreatic cancer cells, melanoma cells, colon cancer cells, or gastric cancer cells. Notably, the compounds of the present invention are also effective when applied to metastatic cell lines, indicating their ability to treat advanced cancer.

[0014] The compounds of the present invention are highly specific and are capable of specifically targeting cancer cells. That is, the compounds are able to distinguish between normal cells and cancer cells. This represents a significant advance in the field of cancer treatment, as most of the side effects of current anti-cancer therapies are due to the lack of specificity of anti-tumor compounds. This specificity for cancer cells also explains the experimental data provided below, supporting the non-toxicity of the compounds when administered to human primary cells (see Figure 13 ).

[0015] These properties render the compounds of formula (I) of the present invention suitable for the treatment of cancer.

[0016] Importantly, the compounds provided herein, despite containing an alkyl carbon chain, exhibit a moderate hydrophobicity, which contributes to their solubility and stability in solution and greatly facilitates their formulation and use in clinical practice.

[0017] The combination of the physicochemical properties and biological activities of the compounds of the present invention makes them an important pharmacological alternative in the treatment of tumors that are currently incurable, such as pancreatic tumors.

[0018] Accordingly, in one aspect, the present invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof or a stereoisomer or a mixture of stereoisomers thereof:

[0019]

[0020] wherein n is an integer from 0 to 10; R1 is a divalent radical selected from CH2, O, NH, and S; and R2 is a (C3-C 15 ) alkyl group.

[0021] In a second aspect, the present invention provides a pharmaceutical composition comprising a therapeutically effective amount of the compound defined in the first aspect, and at least one pharmaceutically acceptable excipient, diluent, or carrier.

[0022] In a third aspect, the present invention provides the compound defined in the first aspect or the pharmaceutical composition defined in the second aspect for use as a medicament.

[0023] In a fourth aspect, the present invention provides the compound defined in the first aspect or the pharmaceutical composition defined in the second aspect for the treatment or prevention of tumor diseases.

[0024] In a fifth aspect, the present invention provides a method for preparing a compound of formula (I) as defined in the first aspect, the method comprising: a) subjecting a compound of formula (II) to an esterification reaction with a compound of formula (III), and b) deprotecting the compound obtained from (a), wherein n is an integer from 0 to 10; R1 is a divalent radical selected from CH2, O, NH, and S; R2 is a (C3-C 15 ) alkyl group; and PG is a hydroxyl protecting group,

[0025] Detailed Description

[0026] Figure 1 is a bar graph showing the inhibitory effect (compared to mock-treated cells) of various different compounds of the present invention on the growth of IGR39 human primary melanoma cells at four different concentrations (from the leftmost column: 0.1 mM; from the second column from the left: 0.2 mM; from the third column from the left: 0.25 mM; from the fourth column from the left: 0.3 mM). The y-axis represents the number of cells after 72 h of treatment as a percentage of the number of mock-treated cells (which is assigned a value of 100%). Compound I a 、I b and I c structures are provided below.

[0027] Figure 2 is a bar graph showing the inhibitory effect (compared to mock-treated cells) of various different compounds of the present invention on the growth of IGR37 human metastatic melanoma cells. The above Figure 1 description regarding the columns, compounds, and y-axis applies equally to this figure.

[0028] Figure 3 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of MW115 human primary melanoma cells (compared to mock-treated cells). Above Figure 1 The descriptions regarding columns, compounds, and the y-axis apply equally to this figure.

[0029] Figure 4 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of MW266.4 human metastatic melanoma cells (compared to mock-treated cells). Above Figure 1 The descriptions regarding columns, compounds, and the y-axis apply equally to this figure.

[0030] Figure 5 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of DLD1 human colon cancer cells (compared to mock-treated cells). Above Figure 1 The descriptions regarding columns, compounds, and the y-axis apply equally to this figure.

[0031] Figure 6 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of SW480 human colon cancer cells (compared to mock-treated cells). Above Figure 1 The descriptions regarding columns, compounds, and the y-axis apply equally to this figure.

[0032] Figure 7 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of HCT116 human colon cancer cells (compared to mock-treated cells). Above Figure 1 The descriptions regarding columns, compounds, and the y-axis apply equally to this figure.

[0033] Figure 8 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of NUG-C4 human gastric cancer cells (compared to mock-treated cells). Above Figure 1 The descriptions regarding columns, compounds, and the y-axis apply equally to this figure.

[0034] Figure 9 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of COLO668 human lung cancer cells (compared to mock-treated cells). Above Figure 1 The descriptions regarding columns, compounds, and the y-axis apply equally to this figure.

[0035] Figure 10 This is a bar graph showing the inhibitory effects of various compounds of the present invention on the growth of BXPC3 human pancreatic cancer cells (compared to mock-treated cells). Above Figure 1The descriptions regarding the columns, compounds, and the y-axis apply equally to this figure.

[0036] Figure 11 It is a bar graph showing the inhibitory effects of various different compounds of the present invention on the growth of CAPAN2 human pancreatic cancer cells (compared with mock-treated cells). Above Figure 1 The descriptions regarding the columns, compounds, and the y-axis apply equally to this figure.

[0037] Figure 12 It is a bar graph showing the inhibitory effects of various different compounds of the present invention on the growth of RWP1 human pancreatic cancer cells (compared with mock-treated cells). Above Figure 1 The descriptions regarding the columns, compounds, and the y-axis apply equally to this figure.

[0038] Figure 13 It is a bar graph showing the inhibitory effects of various different compounds of the present invention on the growth of human primary vascular endothelial cells (compared with mock-treated cells). Above Figure 1 The descriptions regarding the columns, compounds, and the y-axis apply equally to this figure.

[0039] When used in this specification, unless otherwise stated, all terms shall be understood in their common meanings as known in the art. Other more specific definitions of certain terms used in this application are set forth below and are intended to be applied uniformly throughout the specification and claims, unless a more broad definition is provided by an explicitly stated definition.

[0040] When used herein, the indefinite article "a" or "an" is synonymous with "at least one" or "one or more". The definite article, such as "the", as used herein also includes the plural of the noun, unless otherwise indicated.

[0041] As described above, the present invention provides ascorbate esters of formula (I) or pharmaceutically acceptable salts thereof or stereoisomers or mixtures of stereoisomers having potent cancer inhibitory activity.

[0042] As used herein, the term "pharmaceutically acceptable salt", when referring to the compounds of the present invention, means those salts that are suitable for use in contact with the tissues of humans and non-human animals within the scope of reasonable medical judgment, without undue toxicity, irritation, allergic response, etc., and commensurate with a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. Examples of pharmaceutically acceptable non-toxic acid addition salts are salts formed by reacting an amino or thiol group with an inorganic acid such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with an organic acid such as acetic acid, trifluoroacetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipates, alginates, ascorbates, aspartates, benzenesulfonates, benzoates, bisulfates, borates, butyrates, camphorates, camphorsulfonates, citrates, cyclopentanepropionates, digluconates, dodecyl sulfates, ethanesulfonates, formates, fumarates, glucoheptanoates, glycerophosphates, gluconates, hemisulfates, heptanoates, hexanoates, hydroiodides, 2-hydroxyethanesulfonates, lactates, lactobionates, laurates, lauryl sulfates, malates, maleates, malonates, methanesulfonates, 2-naphthalenesulfonates, nicotinates, nitrates, oleates, oxalates, palmitates, pamoates, pectates, persulfates, 3-phenylpropionates, phosphates, picrates, pivalates, propionates, stearates, succinates, sulfates, tartrates, thiocyanates, p-toluenesulfonates, undecanoates, valerates, etc.

[0043] The compounds have asymmetric centers and thus exist in different isomeric forms. All single optical isomers and stereoisomers of the compounds mentioned herein, as well as their mixtures, are considered to be within the scope of the present invention. Thus, any given compound mentioned herein is intended to represent any one of the racemate, one or more stereoisomeric forms, one or more atropisomeric forms, and their mixtures.

[0044] In the present invention, the term "alkyl" encompasses both straight-chain and branched-chain hydrocarbon chains. In certain embodiments, optionally in combination with any of the embodiments provided above or below, "alkyl" refers to a straight-chain hydrocarbon chain.

[0045] Illustrative non-limiting examples of "alkyl" are methyl (C1), ethyl (C2), propyl (C3), isopropyl (C3), isobutyl (C4), sec-butyl (C4), tert-butyl (C4), pentyl (C5), hexyl (C6), heptyl (C7), octyl (C8), nonyl (C9) and decyl (C 10 ) etc.

[0046] In a specific embodiment of the first aspect, optionally in combination with any embodiment provided above or below, n is from 0 to 10, from 1 to 5, or from 2 to 3. In an even more specific embodiment, n is 1, or n is 2.

[0047] In another specific embodiment of the first aspect, optionally in combination with any embodiment provided above or below, R1 is CH2 or O. As shown in the examples below, compounds in which R1 is CH2 are particularly advantageous in cancer treatment.

[0048] In another specific embodiment of the first aspect, optionally in combination with any embodiment provided above or below, R2 is selected from (C4-C 12 ) alkyl, (C4-C9) alkyl, (C5-C8) alkyl, or (C5-C7) alkyl. In an even more specific embodiment, R2 is (C5) alkyl.

[0049] In another specific embodiment of the first aspect, optionally in combination with any embodiment provided above or below, n is 2; R1 is selected from CH2, O, NH, and S; and R2 is (C3-C 15 ) alkyl.

[0050] In another specific embodiment of the first aspect, optionally in combination with any embodiment provided above or below, n is 2, R1 is CH2, and R2 is (C5) alkyl. In another specific embodiment, n is 2, R1 is O, and R2 is (C5) alkyl. In yet another specific embodiment, n is 2, R1 is O, and R2 is (C8) alkyl. In yet another specific embodiment, n is 0, R1 is O, and R2 is (C5) alkyl.

[0051] The most preferred compounds are the compounds selected from Table 1:

[0052] Table 1

[0053] Compound (I) <![CDATA[R1]]> <![CDATA[R2]]> n <![CDATA[I a > O <![CDATA[(C5) alkyl]]> 2 <![CDATA[I b > <![CDATA[CH2]]> <![CDATA[(C5) alkyl]]> 2 <![CDATA[I c > O <![CDATA[(C8) alkyl]]> 2 <![CDATA[I d > O <![CDATA[(C5) alkyl]]> 0 <![CDATA[I e > O <![CDATA[(C5) alkyl]]> 1 <![CDATA[I f > <![CDATA[CH2]]> <![CDATA[(C5) alkyl]]> 1

[0054] The compounds of the present invention can be readily prepared in a flexible manner from commercially available reagents by a variety of different methods.

[0055] Scheme I A specific embodiment illustrating a method for preparing a symmetric compound of formula (I) is as follows:

[0056] Scheme I:

[0057]

[0058] In the above scheme, R is (C3-C 15)Alkyl.

[0059] The preparation of the pharmaceutically acceptable salts of the compounds of formula (I) can be carried out by methods known in the art. For example, they can be prepared from the parent compounds containing basic moieties (NH, SH, OH) by conventional chemical methods. Generally, such salts are prepared, for example, by reacting the free base form of these compounds with a stoichiometric amount of a suitable pharmaceutically acceptable acid in water or an organic solvent or a mixture thereof.

[0060] As disclosed previously, in a second aspect, the present invention also provides a pharmaceutical composition comprising a therapeutically effective amount of a compound of the present invention and at least one pharmaceutically acceptable excipient, diluent or carrier.

[0061] The expression "pharmaceutical composition" encompasses compositions intended for use in humans as well as compositions for other non-human mammals (i.e., veterinary compositions).

[0062] As used herein, the expression "therapeutically effective amount" means an amount of the compound that is sufficient, when administered, to prevent the development of one or more symptoms of the disease (i.e., cancer) being targeted or to alleviate the symptoms to some extent. The specific dose of the compound administered according to the present invention is of course determined by the specific circumstances surrounding the case, including the compound being administered, the route of administration, the specific disorder to be treated and similar considerations.

[0063] The expression "pharmaceutically acceptable excipient, diluent or carrier" means a pharmaceutically acceptable material, composition or vehicle. Each component must be pharmaceutically acceptable in the sense of being compatible with the other ingredients of the pharmaceutical composition. It must also be suitable for use in contact with the tissues or organs of humans and non-human animals without undue toxicity, irritation, allergic response, immunogenicity or other problems or complications, commensurate with a reasonable benefit / risk ratio.

[0064] Examples of suitable pharmaceutically acceptable excipients are solvents, dispersion media, diluents or other liquid vehicles, dispersing or suspending aids, surfactants, isotonic agents, thickening or emulsifying agents, preservatives, solid binders, lubricants, etc. The use of any conventional excipient medium is contemplated within the scope of the present invention, provided that it is not incompatible with the substance or its derivatives, for example by producing any unwanted biological effects or otherwise interacting harmfully with any other component of the pharmaceutical composition.

[0065] In the pharmaceutical compositions of the present invention, the relative amounts of the active ingredient, pharmaceutically acceptable excipient and / or any other ingredient will vary with the identity, size and / or condition of the subject to be treated and further with the route by which the composition is to be administered.

[0066] Pharmaceutically acceptable excipients used in the preparation of pharmaceutical compositions include, but are not limited to, inert diluents, dispersing and / or granulating agents, surfactants and / or emulsifiers, disintegrants, binders, preservatives, buffers, lubricants and / or oils. Excipients such as colorants, coating agents, sweeteners and flavoring agents may be present in the composition, as determined by the formulator.

[0067] The pharmaceutical composition containing the compound of the present invention may exist in any dosage form, such as solid or liquid, and may be administered by any suitable route, such as oral, parenteral, rectal, topical, intranasal or sublingual routes, for which they will include pharmaceutically acceptable excipients necessary for formulating the desired dosage form, such as topical preparations (ointments, creams, lipid gels, hydrogels, etc.), eye drops, aerosol sprays, injection solutions, osmotic pumps, etc.

[0068] Exemplary diluents include, but are not limited to, calcium carbonate, sodium carbonate, calcium phosphate, dibasic calcium phosphate, calcium sulfate, calcium hydrogen phosphate, sodium phosphate, lactose, sucrose, cellulose, microcrystalline cellulose, kaolin, mannitol, sorbitol, inositol, sodium chloride, dried starch, corn starch, powdered sugar, and combinations thereof.

[0069] Exemplary granulating and / or dispersing agents include, but are not limited to, potato starch, corn starch, tapioca starch, sodium starch glycolate, clay, alginic acid, guar gum, citrus pulp, agar, bentonite, cellulose and wood products, natural sponges, cation exchange resins, calcium carbonate, silicates, sodium carbonate, cross-linked polyvinylpyrrolidone (cross-linked povidone), sodium carboxymethyl starch (sodium starch glycolate), carboxymethyl cellulose, cross-linked sodium carboxymethyl cellulose (cross-linked carboxymethyl cellulose), methyl cellulose, pregelatinized starch (starch 1500), microcrystalline starch, water-insoluble starch, calcium carboxymethyl cellulose, magnesium aluminum silicate (Veegum), sodium lauryl sulfate, quaternary ammonium compounds, and combinations thereof.

[0070] Exemplary binders include, but are not limited to, starch (such as corn starch and starch paste), gelatin, sugars (such as sucrose, glucose, dextrose, dextrin, molasses, lactose, lactitol, mannitol), natural and synthetic gums (such as gum arabic, sodium alginate, Irish moss extract, panwar gum, ghatti gum, isapol husks mucilage, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, microcrystalline cellulose, cellulose acetate, polyvinylpyrrolidone), magnesium aluminum silicate (Veegum), larch arabinogalactan, alginates, polyethylene oxide, polyethylene glycol, inorganic calcium salts, silicic acid, polymethacrylates, waxes, water, alcohols, and combinations thereof.

[0071] Exemplary preservatives may include antioxidants, chelating agents, antimicrobial preservatives, antifungal preservatives, alcohol preservatives, acidic preservatives, and other preservatives. Exemplary antioxidants include, but are not limited to, α-tocopherol, ascorbic acid, ascorbyl palmitate, ascorbyl stearate, ascorbyl oleate, butylated hydroxyanisole, butylated hydroxytoluene, monothioglycerol, potassium metabisulfite, propionic acid, propyl gallate, sodium ascorbate, sodium bisulfite, sodium metabisulfite, and sodium sulfite. Exemplary chelating agents include ethylenediaminetetraacetic acid (EDTA), citric acid monohydrate, disodium edetate, dipotassium edetate, edetic acid, fumaric acid, malic acid, phosphoric acid, sodium edetate, tartaric acid, and trisodium edetate.

[0072] Exemplary buffers include, but are not limited to, citrate buffer solutions, acetate buffer solutions, phosphate buffer solutions, ammonium chloride, calcium carbonate, calcium chloride, calcium citrate, calcium gluconolactate, calcium glucoheptonate, calcium gluconate, D-gluconic acid, calcium glycerophosphate, calcium lactate, propionic acid, calcium levulinate, valeric acid, dicalcium phosphate, phosphoric acid, tricalcium phosphate, calcium phosphate, potassium acetate, potassium chloride, potassium gluconate, potassium mixtures, dipotassium phosphate, monopotassium phosphate, potassium phosphate mixtures, sodium acetate, sodium bicarbonate, sodium chloride, sodium citrate, sodium lactate, disodium phosphate, monosodium phosphate, sodium phosphate mixtures, tromethamine, magnesium hydroxide, aluminum hydroxide, alginic acid, pyrogen-free water, isotonic saline, Ringer's solution, ethanol, and combinations thereof.

[0073] Exemplary lubricants include, but are not limited to, magnesium stearate, calcium stearate, stearic acid, silica, talc, malt, glyceryl behenate, hydrogenated vegetable oil, polyethylene glycol, sodium benzoate, sodium acetate, sodium chloride, leucine, magnesium lauryl sulfate, sodium lauryl sulfate, and combinations thereof.

[0074] As described above, the third aspect of the present invention provides the compounds or pharmaceutical compositions of the present invention for use as a medicine.

[0075] As described above, in a fourth aspect, the present invention provides the compounds or pharmaceutical compositions of the present invention for the treatment or prevention of tumor diseases. Without wishing to be bound by theory, due to the metabolic changes occurring in cancer cells, the compounds of the present invention specifically target these cells. Accordingly, the compounds of the present invention can be used to treat any type of cancer, including non-solid tumors such as leukemia.

[0076] The term "treatment" includes, but is not limited to, inhibiting, slowing down, stopping, reducing, improving, or reversing the progression or severity of existing symptoms, clinical signs, disorders, conditions, or diseases. Treatment can be by therapeutic administration or dosing.

[0077] The term "prevention" includes, but is not limited to, reducing, lowering, or ameliorating the risk of symptoms, clinical signs, disorders, conditions, or diseases and protecting a subject from symptoms, clinical signs, disorders, conditions, or diseases. Prevention may be effected by prophylactic administration or dosing.

[0078] This aspect may also be conceived as the use of a compound or pharmaceutical composition of the invention in the preparation of a medicament for the treatment or prevention of a neoplastic disease. This aspect may also be conceived as a method of treating or preventing a neoplastic disease, the method comprising administering to a subject in need thereof a therapeutically effective amount of a compound of the invention and a pharmaceutically acceptable excipient or carrier.

[0079] As used herein, the term "neoplastic disease" refers to cancer of any type and origin and its precursor stages. Illustrative non-limiting examples of neoplastic diseases that may be treated with the compounds, conjugates, and pharmaceutical compositions of the invention include, but are not limited to, papilloma, adenomas, lipoma, osteoma, myoma, hemangioma, nevus, mature teratoma, carcinoma, sarcoma, immature teratoma, melanoma, myeloma, leukemia, Hodgkin's lymphoma, basalioma, spinalioma, breast cancer, ovarian cancer, uterine cancer, lung cancer, bronchial cancer, prostate cancer, colon cancer, gastric cancer, pancreatic cancer, kidney cancer, esophageal cancer, liver cancer, head and neck cancer, and the like. The term neoplastic disease is intended to encompass both primary and metastatic tumors.

[0080] In a specific embodiment of the fourth aspect, optionally in combination with any of the embodiments provided above or below, the neoplastic disease is selected from pancreatic cancer, melanoma, colon cancer, gastric cancer, and lung cancer. More specifically, the neoplastic disease is pancreatic cancer.

[0081] The compounds of the invention may be used in the same manner as other known chemotherapeutic agents. In addition, they may be used alone or in combination with other suitable anti-cancer agents. Examples of anti-cancer agents include, but are not limited to, chemotherapeutic agents, growth inhibitors, cytotoxic agents, agents used in radiotherapy, anti-angiogenic agents, anti-lymphangiogenic agents, apoptotic agents, anti-tubulin agents, and other agents for the treatment of cancer, such as anti-HER-2 antibodies, anti-CD20 antibodies, epidermal growth factor receptor (EGFR) antagonists (e.g., tyrosine kinase inhibitors), HER1 / EGFR inhibitors (e.g., erlotinib (Tarceva TM )), platelet-derived growth factor inhibitors (e.g., imatinib (Gleevec TM)(Imatinib Mesylate)), COX-2 inhibitors (such as celecoxib), interferons, cytokines, antagonists (such as neutralizing antibodies) that bind to one or more of the target points ErbB2, ErbB3, ErbB4, PDGFR-β, BlyS, APRIL, BCMA, VEGF or VEGF receptors, TRAIL / Apo2 and other bioactive and organic chemical agents, etc. Their combinations are also included in the present invention.

[0082] As described above, in the fifth aspect, the present invention provides a method for preparing the compound of formula (I) defined in the first aspect.

[0083] Examples of hydroxyl protecting groups can be found in the following literature: T.W. Greene and P.G.M. Wuts, "Protective Groups in Organic Synthesis", Chapter 2, "Protection for the hydroxyl Group, Including 1,2- and 1,3-Diols", John Wiley & Sons, Inc., 1999, pp. 17-245. Representative hydroxyl protecting groups include protecting groups in which the hydroxyl group is acylated or alkylated, such as benzyl methyl and triethyl ether, as well as alkyl ethers, tetrahydropyranyl ethers, trialkyl ethers such as tert-butyldimethylsilyl (TBS), tert-butyldiphenyl (TBDPS), allyl ethers and benzyl esters.

[0084] In a specific embodiment of the fifth aspect, optionally in combination with any embodiment provided above or below, the protecting group (PG) is a benzyl ester.

[0085] The introduction and removal of the protecting group can be carried out by methods known in the art (see T.W. Greene, etc.). Specific conditions depend on the protecting group used. In a specific application, when using the Bn group, it can be introduced by reacting with benzyl bromide in the presence of a suitable solvent. Deprotection can be carried out by reacting with Pd / C in methanol.

[0086] Throughout the specification and claims, the word "comprising" and its variations are not intended to exclude other technical features, additives, components or steps. Additionally, the word "comprising" encompasses the case of "consisting of". For those skilled in the art, other objectives, advantages and features of the present invention will become apparent upon studying this specification or can be learned through the practice of the present invention. The following examples and drawings are provided for illustration and are not intended to limit the present invention. The reference numerals in parentheses in the claims and related to the drawings are only used to attempt to enhance the understandability of the claims and should not be construed as limiting the scope of the claims. Furthermore, the present invention encompasses all possible combinations of the specific and preferred embodiments described herein.

[0087] Example

[0088] Example 1: Preparation of (R)-3,4-bis(benzyloxy)-5-((S)-2,2-dimethyl-1,3-dioxolan-4-yl)furan-2(5H)-one (Compound 2) Example 2: Preparation of (R)-3,4-bis(benzyloxy)-5-((S)-1,2-dihydroxymethyl)furan-2(5H)-one (Compound 3)

[0089]

[0090] Compound 1 (5.55 g, 25.6 mmol) and potassium carbonate powder (10.6 g, 77 mmol) were suspended in acetone (80 ml). After refluxing (60 °C), benzyl bromide (mg, mmol) was added and the mixture was refluxed for an additional 16 h. The solvent was removed under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (20%) to obtain Compound 2 (8.14 g, 80%). Compound 2: Colorless oil, Rf: 0.67 (70% ethyl acetate / hexane). IR (ATR, cm -1 ): 1763, 1677, 1316, 1213, 1148, 1068. EM (ESI) [m / z, (%)]: 419.14 (M + +Na, 13), 397.16 (M + +1, 100). EMAR (ESI): The calculated value for C 23 H 25 O6 is 397.1646, and the measured value is 397.1651.

[0091] Example 3. Preparation of 4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexan-1-ol (Compound 5) Example 4. Preparation of tert-butyl ((4-(pentyloxy)cyclohexyl)methoxy)diphenylsilane (Compound 6)

[0092]

[0093] Compound 2 (5.9 g, 14.9 mmol) was dissolved in CH3CN (240 ml), then 3M aqueous HCl solution (20 ml) was added, and the reaction mixture was stirred at 30 °C for 2 h. The solvent was removed under reduced pressure, and the residue was diluted in EtOAc. The organic layer was washed successively with brine, then dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (60%) to give compound 3 (5.2 g, 98%). Compound 3: Colorless oil, Rf: 0.17 (70% ethyl acetate / hexane). IR (ATR, cm -1 ): 3391, 2925, 1748, 1666, 1317, 1152, 1067, 697. EM (ESI) [m / z, (%)]: 379.11 (M + +Na, 5), 357.13 (M + +1, 100). EMAR (ESI): Calculated for C 20 H 21 O6 is 357.1333, found 357.1333.

[0094] Example 5. Preparation of (4-(pentyloxy)cyclohexyl)methanol (Compound 7)

[0095]

[0096] To a solution of diol 4 (910 mg, 6.99 mmol) in DMF (15 ml) was added imidazole (1.9 g, 28 mmol), a catalytic amount of DMAP and TBDPSCl (2 ml, 7.69 mmol), and the mixture was stirred at room temperature for 2 h. The solvent was evaporated, H2O (10 ml) was added, and the product was extracted with CH2Cl2 (3 x 10 ml). The organic layer was dried over Na2SO, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (30%) to give compound 5 (2.4 g, 93%). Compound 5: Colorless oil, Rf: 0.85 (50% ethyl acetate / hexane). IR (ATR, cm -1 ): 3350, 2927, 2859, 1427, 1110, 701. EM (ESI) [m / z, (%)]: 369.22 (M + +1, 100), 351.21 (M + -OH, 21). EMAR (ESI): Calculated for C 23 H 33 O2Si is 369.2244, found 369.2241.

[0097] Example 6. Preparation of (E)-ethyl 3-(4-(pentyloxy)cyclohexyl)acrylate (Compound 8)

[0098]

[0099] At 0 °C, NaH (60%) (3.02 g, 75.6 mmol) was added to a solution of compound 5 (9.3 g, 25.2 mmol) in THF (90 ml) and DMSO (12 ml), and the mixture was cooled to 50 °C. After 30 min, iodopentane (11.5 ml, 88.2 mmol) was added, and the mixture was allowed to reflux for an additional 21 h. The reaction was quenched with H2O (20 ml) and it was extracted with AcOEt (3 x 20 ml). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (3%) to give compound 6 (3.81 g, 35%), and purified with ethyl acetate - hexane (30%) to give compound 5 (starting material) (5.45 g, 50%). Compound 6: colorless oil, Rf: 0.95 (20% ethyl acetate / hexane). IR (ATR, cm -1 ): 2929, 2856, 1427, 1109, 701. EM (ESI) [m / z, (%)]: 439.30 (M + +1, 7), 361.25 (100), 183.17 (M + -OTBDPS, 68). EMAR (ESI): C 28 H 43 The calculated value for O2Si is 439.3026, and the measured value is 439.2694.

[0100] Example 7. Preparation of 3-(4-(pentyloxy)cyclohexyl)propanoic acid (Compound 9)

[0101]

[0102] To a solution of 6 (3.79 g, 8.63 mmol) in THF (20 ml) at room temperature was added 1.0 M TBAF solution (17 ml, 17 mmol), and the mixture was stirred under the same conditions for 16 h. The solvent was evaporated, and the residue was chromatographed on silica gel using ethyl acetate - hexane (30%) as the eluent to give compound 7 (1.28 g, 75%). Compound 7: colorless oil, Rf: 0.42 (30% ethyl acetate / hexane). IR (ATR, cm -1 ): 3371, 2928, 2857, 1451, 1090, 1036. EM (ESI) [m / z, (%)]: 201.18 (M + +1, 45), 183.17 (M + -OH, 100). EMAR (ESI): C12 H 25 The calculated value of H2O is 201.1849, and the measured value is 201.1847.

[0103] Example 8. Preparation of (S)-2-((R)-3,4-bis(benzyloxy)-5-oxo-2,5-dihydrofuran-2-yl)-2-hydroxyethyl 3-(4-(pentyloxy)cyclohexyl)propanoate (Compound 10)

[0104]

[0105] To a solution of compound 7 (1.13 g, 5.64 mmol) in CH2Cl2 (20 ml) were added molecular sieves (850 mg), NMO (1.98 g, 16.9 mmol) and a catalytic amount of TPAP, and the mixture was stirred at room temperature for 1 h. The reaction was filtered through celite. The solvent was evaporated off, and the residue was dissolved in THF (10 ml). Ph3P=CHCO2Et (3.94 g, 11.3 mmol) was added, and the mixture was stirred for 2 days. The solvent was evaporated off, and the residue was chromatographed on silica gel using ethyl acetate - hexane (5%) as the eluent to give compound 8 (787 mg, 52%). Compound 8: colorless oil, Rf: 0.68 (10% ethyl acetate / hexane). IR (ATR, cm -1 ) : 2931, 2858, 1720, 1652, 1267, 1173, 1096. EM (ESI) [m / z, (%)] : 269.21 (M + +1, 52), 223.16 (33), 181.12 (100). EMAR (ESI) : C 16 H 29 The calculated value of C15H17O3 is 269.2111, and the measured value is 269.2107.

[0106] Example 9: Preparation of 2-(3,4-dihydroxy-5-oxo-2,5-dihydrofuran-2-yl)-2-hydroxyethyl 3-(4-(pentyloxy)cyclohexyl)propanoate (Compound Ia)

[0107]

[0108] To a mixture of compound 8 (450 mg, 1.67 mmol) in ethyl acetate (15 ml) was added a catalytic amount of Pd / C (10%), and the suspension was stirred at room temperature under H2 for 14 h. Then the mixture was filtered through celite and the filtrate was rotary evaporated. The residue was dissolved in THF / H2O (1:1, 7 ml), LiOH·H2O was added, and the mixture was stirred for 18 h. The solvent was evaporated off, and the residue was chromatographed on silica gel using ethyl acetate - hexane (30%) as the eluent to give compound 9 (360 mg, 89%). Compound 9: colorless oil, Rf: 0.45 (20% ethyl acetate / hexane). IR (ATR, cm -1):3031, 2927, 2856, 2782, 1707, 1453, 1089. EM(ESI)[m / z, (%)]:397.33(100), 243.19(M + +1, 67). EMAR(ESI):C 14 H 27 The calculated value of C

[0109] Example 10. Preparation of 4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexan-1-ol (Compound 2) Example 11. Preparation of (E)-ethyl 3-((4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexyl)oxy)acrylate (Compound 3)

[0110]

[0111] To a stirred solution of compound 9 (172 mg, 0.70 mmol) in CH2Cl2 (5 ml) was added DIC (120 μl, 0.77 mmol) and DMAP (72 mg, 0.70 mmol), and the mixture was stirred for 30 minutes. Protected vitamin C 3 (379 mg, 1.06 mmol) in CH2Cl2 (4 ml) was added dropwise, and the reaction mixture was stirred at room temperature overnight and then filtered. The filtrate was concentrated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (12%) to give compound 10 (193 mg, 48%). Compound 10: Colorless oil, Rf: 0.43 (30% ethyl acetate / hexane). IR(ATR, cm -1 ):3415, 2926, 2856, 1765, 1742, 1674, 1454, 1320, 1153. EM(ESI)[m / z, (%)]:581.30(M + +1, 100). EMAR(ESI):C 34 H 45 The calculated value of C

[0112] Example 12. Preparation of ethyl 3-((4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexyl)oxy)propanoate (Compound 4) Example 13. Preparation of 3-((4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexyl)oxy)propanal (Compound 5) and 3-((4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexyl)oxy)propan-1-ol (Compound 6)

[0113]

[0114] To a mixture of compound 10 (193 mg, 0.33 mmol) in methanol (10 ml) was added a catalytic amount of Pd / C (10%), and the suspension was stirred at room temperature under H2 for 14 h. Then the mixture was filtered through Celite, and the filtrate was rotary evaporated to give compound Ia (131 mg, 98%). Compound Ia: Colorless oil, Rf: 0.10 (ethyl acetate). IR(ATR, cm -1):3367,2925,2854,1740,1668,1346,1116。 1 H-NMR (MeOD-d4, δ): 4.75 (d, J = 2.1 Hz, 1H, H-4), 4.25 (m, 2H, H-6), 4.11 (m, 2H, H-5), 3.49 (m, 1H, H-7’), 3.41 (t, J = 6.5 Hz, 2H, H-8’), 2.41 (t, J = 7.7 Hz, 2H, H-2’), 1.92 (m, 3H), 1.52 (m, 4H), 1.36 (m, 9H), 0.93 (m, 3H) ppm. 13 C-NMR (MeOD-d4, δ): 174.0 (C-1’), 173.9 (C-1’), 171.7 (C-1), 152.6 (C-3), 118.7 (C-2), 78.3 (CH-7’), 75.8 (CH), 73.9 (CH-7’), 67.9 (CH2-8), 67.5 (CH2-8), 66.7 (CH), 64.5 (CH2-6), 36.5 (CH-4), 35.9 (CH-4), 31.8 (CH2), 31.4 (CH2), 31.3 (CH2), 31.2 (CH2), 31.1 (CH2), 30.6 (CH2), 29.5 (CH2), 29.0 (CH2), 28.3 (CH2), 28.1 (CH2), 26.8 (CH2), 22.2 (CH2), 22.2 (CH2), 13.2 (CH3-12’), 13.1 (CH3-12’) ppm. EM (ESI) [m / z, (%)]: 401.21 (M + +1, 100), 369.31 (35). EMAR (ESI): C 20 H 33 The calculated value of C

[0115] Example 14. Preparation of (E)-tert-butyl ((4-(oct-3-en-1-yloxy)cyclohexyl)methoxy)diphenylsilane (Compound 7) Example 15. Preparation of tert-butyl ((4-(octyloxy)cyclohexyl)methoxy)diphenylsilane (Compound 8)

[0116]

[0117] It should be noted that there seems to be an incomplete part in the original text for item . It says "The calculated value of C " without the full expression. You may want to check and correct it if necessary.To a solution of Compound 1 (5.0 g, 0.03 mol) in DMF (100 ml) was added imidazole (10.5 g, 0.15 mol), a catalytic amount of DMAP, and TBDPSCl (10.5 ml, 0.04 mol), and the mixture was stirred at room temperature for 4 h. The solvent was evaporated off, ethyl acetate (20 ml) was added, and the product was washed with H2O (3 x 20 ml). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated off under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (15%) to give Compound 2 (13.9 g, 99%). Compound 2: Colorless oil, Rf: 0.60 (30% ethyl acetate / hexane). IR (ATR, cm -1 ): 3350, 2927, 2859, 1427, 1110, 701. MS (ESI) [m / z, (%)]: 369 ([M + +1], 100), 351 ([M + -OH], 21). HR-MS (ESI): Calculated for C 23 H 33 O2Si is 369.2244, found 369.2241.

[0118] Example 17. Preparation of 4-(octyloxy)cyclohexane-1-carbaldehyde (Compound 10) Example 19. Preparation of 3-(4-(octyloxy)cyclohexyl)propanoic acid (Compound 12)

[0119]

[0120] To a solution of 2 (372 mg, 1.01 mmol) and DABCO (23 mg, 0.20 mmol) in CH2Cl2 (8 ml) at room temperature was added HCCCO2Et (154 μL, 1.50 mmol), and the mixture was stirred for 10 h. The solvent was evaporated off, and the residue was chromatographed on silica gel using ethyl acetate - hexane (5%) as the eluent to give Compound 3 (420 mg, 90%). Compound 3: Colorless oil, Rf: 0.67 (30% ethyl acetate / hexane). IR (ATR, cm -1 ): 2931, 2899, 2857, 1706, 1640. MS (ESI) [m / z, (%)]: 467 ([M + +1], 100), 425 (26), 352 (23), 351 (76). HR-MS (ESI): Calculated for C 28 H 39 O4Si is 467.2612, found 467.2614.

[0121] Example 20. Preparation of (S)-2-((R)-3,4-bis(benzyloxy)-5-oxo-2, ​

[0122]

[0123] To a mixture of MeOH (5 ml) containing compound 3 (295 mg, 0.63 mmol) was added a catalytic amount of Pd / C (10%), and the suspension was stirred at room temperature under H2 for 24 h. The mixture was then filtered through celite, and the filtrate was rotary evaporated. The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure to give compound 4 (292 mg, 99%). Compound 4: colorless oil, Rf: 0.63 (30% ethyl acetate / hexane). IR (ATR, cm -1 ): 2929, 2894, 2856, 1735. MS(ESI)[m / z,(%)]: 469([M + +1],36),467(13),391(46),351(56),349(45),144(100). HR-MS(ESI):C 28 H 41 The calculated value of O4Si is 469.2769 and the measured value is 469.2775.

[0124] ​ ​ ​

[0125]

[0126] To a solution of compound 4 (352 mg, 0.75 mmol) in CH2Cl2 (7 ml) was added a 1.0 M hexane solution of DIBAL-H (1.1 ml, 1.13 mmol) at -78°C, and the reaction mixture was stirred for 30 minutes. t BuOMe (10 ml) and H2O (300 μL), maintaining vigorous stirring until an off-white gel is formed. Next, add 4N NaOH solution (300 μL), H2O (300 μL) and extend stirring until a white solid is formed. The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate-hexane (5%) to give compounds 5 (285 mg, 90%) and 6 (28 mg, 9%). Compound 5: colorless oil, Rf: 0.50 (20% ethyl acetate / hexane). IR (ATR, cm -1 ): 2929, 2896, 2856, 1725. MS(ESI)[m / z,(%)]: 447([M + +Na],31),426([M + +2],31),425([M ++1],88),351(100),347(80). HR-MS(ESI): C 26 H 36 The calculated value of NaO3Si for C -1 H + is 447.2326, and the measured value is 447.2324. Compound 6: Colorless oil, Rf: 0.17 (20% ethyl acetate / hexane). IR(ATR, cm + ) : 3411, 2927, 2889, 2855. MS(ESI)[m / z,(%)]: 449([M 26 H 38 + Na], 4), 391(12), 349([M

[0127] ​ ​

[0128]

[0129] To a suspension of IPh3PC5H 11 (842 mg, 1.83 mmol) in THF (10 ml) cooled to 0 °C was added 2.5 M n-BuLi solution (731 μL, 1.83 mmol), and the mixture was stirred for 1 h. Compound 5 (195 mg, 0.46 mmol) in THF (3 ml) was added, and stirring was continued at room temperature for 7.5 h. The reaction was quenched with saturated NaHCO3 solution (20 ml), and it was extracted with ethyl acetate (3 x 15 ml). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (2%) to give Compound 7 (170 mg, 78%). Compound 7: Colorless oil, Rf: 0.94 (20% ethyl acetate / hexane). IR(ATR, cm -1 ) : 2948, 2933, 2889, 2854. MS(ESI)[m / z,(%)]: 479([M + + 1], 42), 351(46), 280(21), 279(100). HR-MS(ESI): C 31 H 47 O2Si is calculated to be 479.3340, and the measured value is 479.3328.

[0130] ​

[0131]

[0132] A catalytic amount of Pd / C (10%) was added to a mixture of compound 7 (90 mg, 0.19 mmol) in MeOH (5 ml), and the suspension was stirred at room temperature under H2 for 24 h. The mixture was then filtered through Celite, and the filtrate was rotary evaporated. The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure to give compound 8 (88 mg, 98%). Compound 8: Colorless oil, Rf: 0.93 (20% ethyl acetate / hexane). IR (ATR, cm -1 -1): 2952, 2928, 2897, 2856. MS (ESI) [m / z, (%)]: 479 ([M + +1], 42), 351(46), 280(21), 279(100). HR-MS (ESI): C 31 H 47 O2Si calcd for 479.3340, found 479.3328.

[0133] Example 16. Preparation of (4-(octyloxy)cyclohexyl)methanol (Compound 9)

[0134]

[0135] To a solution of compound 8 (420 mg, 0.87 mmol) in THF (5 ml) at room temperature was added 1.0 M TBAF solution (1.3 ml, 1.31 mmol), and the mixture was stirred under the same conditions for 24 h. The solvent was evaporated, and the residue was chromatographed on silica gel using ethyl acetate - hexane (10%) as the eluent to give compound 9 (194 mg, 93%). Compound 9: Colorless oil, Rf: 0.28 (20% ethyl acetate / hexane). IR (ATR, cm -1 -1): 3314, 2925, 2855, 1443. MS (ESI) [m / z, (%)]: 279(23), 265([M + +Na], 100), 227(26), 225(49). HR-MS (ESI): C 15 H 30 NaO2 calcd for 265.2138, found 265.2133.

[0136] ​

[0137]

[0138] To a solution of compound 9 (194 mg, 0.80 mmol) in CH2Cl2 (5 ml) was added a catalytic amount of TEMPO and BAIB (387 mg, 1.20 mmol), and the mixture was stirred at room temperature for 2 h. The solvent was evaporated off, BuOMe (5 ml) was added, and the product was washed with 15% Na2S2O3 (3 x 10 ml) and saturated NaHCO3 solution (3 x 10 ml). The solvent was evaporated off under reduced pressure, and the residue was purified by column chromatography using ethyl acetate - hexane (1%) to give compound 10 (173 g, 90%). Compound 10: Colorless oil, Rf: 0.67 (20% ethyl acetate / hexane). IR (ATR, cm t ):2925, 2854, 1702, 1455, 1066. MS (ESI) [m / z, (%)]: 257 (100), 241 ([M -1 + 1], 4), 146 (22), 144 (46). HR-MS (ESI): C + H 15 H 29 O2 calculated value is 241.2162, measured value is 241.2142.

[0139] Example 18. Preparation of Ethyl (E)-3-(4-(octyloxy)cyclohexyl)acrylate (Compound 11)

[0140]

[0141] To a solution of compound 10 (165 mg, 0.68 mmol) in THF (5 ml) was added Ph3P=CHCO2Et (479 mg, 1.37 mmol), and the mixture was stirred at room temperature for 24 h. The reaction was quenched with H2O (10 ml) and it was extracted with ethyl acetate (3 x 10 ml). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated off under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (1%) to give compound 11 (153 mg, 72%). Compound 11: Colorless oil, Rf: 0.72 (20% ethyl acetate / hexane). IR (ATR, cm -1 ):2927, 2855, 1721, 1652, 1465. MS (ESI) [m / z, (%)]: 312 (26), 311 ([M + + 1], 100), 181 (55), 146 (32), 144 (60), 131 (32). HR-MS (ESI): C 19 H 35 O3 calculated value is 311.2581, measured value is 311.2573.

[0142] ​

[0143]

[0144] A catalytic amount of Pd / C (10%) was added to a mixture of compound 11 (160 mg, 0.51 mmol) in MeOH (5 ml), and the suspension was stirred at room temperature under H2 for 24 h. The mixture was then filtered through Celite, and the filtrate was rotary evaporated. The residue was dissolved in THF / H2O (1:1, 8 ml) and LiOH·H2O (32 mg, 0.80 mmol) was added, and the mixture was stirred at room temperature for 23 h. 10% HCl (4 ml) was added, and the product was extracted with CH2Cl2 (3 x 5 ml). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (30%) to give compound 12 (137 mg, 95%). Compound 12: colorless oil, Rf: 0.80 (50% ethyl acetate / hexane). IR (ATR, cm -1 ) : 3461, 3001, 2925, 2854, 1709, 1455, 1275. MS (ESI) [m / z, (%)] : 302 (11), 285 ([M + +1], 100), 155 (31), 144 (34). HR-MS (ESI) : C 17 H 33 The calculated value for C

[0145] ​ Preparation of 2-(3,4-dihydroxy-5-oxo-2,5-dihydrofuran-2-yl)ethyl 3-(4-(octyloxy)cyclohexyl)propionate (Compound 13)

[0146]

[0147] DIC (44.0 μl, 0.35 mmol) and DMAP (33 mg, 0.32 mmol) were added to a stirred solution of compound 12 (90 mg, 0.32 mmol) in CH2Cl2 (5 ml), and the mixture was stirred for 10 min. Protected vitamin C 3 (171 mg, 0.48 mmol) in CH2Cl2 (5 ml) was added dropwise, and the reaction mixture was stirred at room temperature for 6 h and then filtered. The filtrate was concentrated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (10%) to give compound 13 (108 mg, 54%). Compound 13: colorless oil, Rf: 0.53 (30% ethyl acetate / hexane). IR (ATR, cm -1):3404,2925,2853,1767,1743,1673,1454,1320. MS(ESI)[m / z,(%)]:640(19),623([M + +1],100),411(15),146(38),144(93),131(35). HR-MS(ESI):C 37 H 51 The calculated value of C

[0148] Example 21. 2-(3,4-Dihydroxy-5-oxo-2,5-dihydrofuran-2-yl)ethyl 3-(4-(octyloxy)cyclohexyl)propionate (2 - base)-2 - hydroxyethyl ester (Compound I c ) Preparation

[0149]

[0150] To a mixture of compound 13 (104 mg, 0.17 mmol) in methanol (4 ml) was added a catalytic amount of Pd / C (10%), and the suspension was stirred at room temperature under H2 for 5 h. Then the mixture was filtered through celite, and the filtrate was rotary evaporated to give compound 14 (63 mg, 84%). Compound 14: colorless oil, Rf: 0.10 (ethyl acetate). IR(ATR, cm -1 ):3337,2967,2929,2874,1721,1613,1562,1522. 1 1H-NMR(MeOD-d4, δ): 4.75 (m, 1H, CH-2” / 3”), 4.16 (m, 3H, CH-2” / 3”, CH2-1”), 3.49 (m, 1H, CH2-1’ / CH-7), 3.41 (t, J = 6.5 Hz, 2H, CH2-1’ / CH-7), 2.40 (m, 2H, CH2-2), 1.86 (m, 2H), 1.45 (m, 21H), 0.92 (t, J = 6.6 Hz, 3H, CH3-8’) ppm. 1313C NMR (MeOD-d4, δ): 174.4 (CO), 170.2 (CO), 162.7 (C-7”), 137.0 (C-6”), 75.8 (CH-7 / 3”), 73.8 (CH-7 / 3”), 72.9 (CH2-1’), 67.5 (CH2-1”), 66.6 (CH-2”), 64.2 (CH2), 35.9 (CH-4), 31.8 (CH2), 31.6 (CH2), 31.2 (CH2), 31.1 (CH2), 29.8 (CH2), 29.2 (CH2), 29.1 (CH2), 28.9 (CH2), 26.7 (CH2), 26.1 (CH2), 22.3 (CH2), 13.6 (CH3-8’) ppm. MS (ESI) [m / z, (%)]: 533 (100), 443 ([M + +1], 40), 411 (23), 144 (31). HR-MS (ESI): C 23 H 38 The calculated value of C

[0151] Example 22. Preparation of 4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexan-1-ol (Compound 2) Example 23. Preparation of 4-(((tert-butyldiphenylsilyl)oxy)methyl)cyclohexan-1-one (Compound 3)

[0152]

[0153] To a solution of diol 1 (5.0 g, 0.03 mol) in DMF (100 ml) was added imidazole (10.5 g, 0.15 mol), a catalytic amount of DMAP and TBDPSCl (10.5 ml, 0.04 mol), and the mixture was stirred at room temperature for 4 h. The solvent was evaporated off, ethyl acetate (20 ml) was added, and the product was washed with H2O (3 x 20 ml). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated off under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (15%) to give compound 2 (13.9 g, 99%). Compound 2: Colorless oil, Rf: 0.60 (30% ethyl acetate / hexane). IR (ATR, cm -1 -1): 3350, 2927, 2859, 1427, 1110, 701. MS (ESI) [m / z, (%)]: 369 ([M + +1], 100), 351 ([M + -OH], 21). HRMS (ESI): C 23 H 33 The calculated value of C

[0154] Example 24. Preparation of tert-butyl ((4-hexylidenecyclohexyl)methoxy)diphenylsilane (Compound 4) Example 25. Preparation of (4-hexylidenecyclohexyl)methanol (Compound 5)

[0155]

[0156] To a solution of Compound 2 (1.4 g, 3.77 mmol) in CH2Cl2 (20 mL) were added molecular sieves (1.4 g), NMO (1.3 g, 11.30 mmol), and a catalytic amount of TPAP, and the mixture was stirred at room temperature for 45 minutes. The reaction was filtered through diatomaceous earth and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (10%) to give Compound 3 (1.0 g, 74%). Compound 3: Colorless oil, Rf: 0.70 (30% ethyl acetate / hexane). IR (ATR, cm -1 ) : 2953, 2928, 2856, 1713. MS (ESI) [m / z, (%)] : 389 ([M + +Na], 3), 289 ([M + -Ph], 100). HRMS (ESI) : C 23 H 30 The calculated value for NaO2Si is 389.1907, and the measured value is 389.1906.

[0157] Example 26. Preparation of ethyl (E)-3-(4-hexylidenecyclohexyl)acrylate (Compound 6)

[0158]

[0159] To a suspension of [Ph3PC6H 13 Br (6.0 g, 13.95 mmol) in THF (10 mL) cooled to 0 °C was added 2.5 M n-BuLi solution (5.1 mL, 12.70 mmol), and the mixture was stirred for 1 h. A solution of Compound 3 (852 mg, 2.30 mmol) in THF (5 mL) was added, and the mixture was stirred at room temperature for 48 h. The reaction was quenched with saturated NaHCO3 solution (20 mL) and it was extracted with t BuOMe (3 x 20 mL). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (1%) to give Compound 4 (845 mg, 84%). Compound 4: Colorless oil, Rf: 0.82 (10% ethyl acetate / hexane). IR (ATR, cm -1 ) : 2954, 2926, 2855. MS (ESI) [m / z, (%)] : 435 ([M + +1], 40), 265 (100). HRMS (ESI) : C 29 H43 The calculated value of OSi is 435.3077, and the measured value is 435.3073.

[0160] Example 27. Preparation of ethyl 3-(4-hexylcyclohexyl)propionate (Compound 7)

[0161]

[0162] At room temperature, 1.0 M TBAF solution (6.6 ml, 6.60 mmol) was added to a solution of compound 4 (2.4 g, 5.50 mmol) in THF (20 ml), and the mixture was stirred for 19 h under the same conditions. The solvent was evaporated, and the residue was chromatographed on silica gel using ethyl acetate - hexane (5%) as the eluent to obtain compound 5 (1.0 g, 99%). Compound 5: colorless oil, Rf: 0.30 (10% ethyl acetate / hexane). IR (ATR, cm -1 ) : 3338, 2953, 2917, 2852. MS (ESI) [m / z, (%)] : 198 (15), 197 ([M + +1], 100), 179 (19). HRMS (ESI) : C 13 H 25 The calculated value of O is 197.1899, and the measured value is 197.1898.

[0163] Example 28. Preparation of 3-(4-hexylcyclohexyl)propionic acid (Compound 8)

[0164]

[0165] To a solution of compound 5 (213 mg, 1.17 mmol) in CH2Cl2 (4 ml) were added molecular sieves (200 mg), NMO (411 mg, 3.51 mmol) and a catalytic amount of TPAP, and the mixture was stirred at room temperature for 1 h. The reaction was filtered under celite. The solvent was evaporated, and the residue was dissolved in THF (5 ml), Ph3P=CHCO2Et (850 mg, 2.34 mmol) was added, and the mixture was stirred for 23 h. The solvent was evaporated, and the residue was chromatographed on silica gel using ethyl acetate - hexane (1%) as the eluent to obtain compound 6 (204 mg, 66%). Compound 6: colorless oil, Rf: 0.42 (5% ethyl acetate / hexane). IR (ATR, cm -1 ) : 3404, 2955, 2923, 2870, 2854, 1718, 1650. MS (ESI) [m / z, (%)] : 266 (18), 265 ([M + +1], 100). HRMS (ESI) : C 17 H 29The calculated value of O2 is 265.2162, and the measured value is 265.2159.

[0166] Example 29. Preparation of (S)-2-((R)-3,4-bis(benzyloxy)-5-oxo-2,5-dihydrofuran-2-yl)ethyl 3-(4-hexylcyclohexyl)propionate (Compound 9)

[0167]

[0168] To a mixture of MeOH (5 ml) containing compound 6 (555 mg, 2.10 mmol) was added a catalytic amount of Pd / C (10%), and the suspension was stirred at room temperature under H2 for 24 h. The mixture was then filtered through Celite, and the filtrate was rotary evaporated. The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure to give compound 7 (550 mg, 99%). Compound 7: colorless oil, Rf: 0.70 (20% ethyl acetate / hexane). IR (ATR, cm -1 ) : 2954, 2918, 2870, 2850, 1736. MS (ESI) [m / z, (%)] : 270 (19%), 269 ([M + + 1], 100). HRMS (ESI) : C 17 H 33 The calculated value of O2 is 269.2475, and the measured value is 269.2473.

[0169] Example 30. (S)-2-((R)-3,4-Dihydroxy-5-oxo-2,5-dihydrofuran-2-yl)ethyl 3-(4-hexylcyclohexyl)propionate

[0170]

[0171] To a solution of THF / H2O (1:1, 4 ml) containing compound 7 (169 mg, 0.63 mmol) was added LiOH·H2O (79 mg, 1.89 mmol), and the mixture was stirred at room temperature for 7 days. 10% HCl (2 ml) was added, and the product was extracted with CH2Cl2 (3 x 5 ml). The organic layer was dried over Na2SO4, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (10%) to give compound 8 (142 mg, 94%). Compound 8: colorless oil, Rf: 0.40 (20% ethyl acetate / hexane). IR (ATR, cm -1 ) : 3039, 2955, 2918, 2870, 2850, 1705. MS (ESI) [m / z, (%)] : 241 ([M + + 1], 100), 223 (44), 219 (63), 205 (65). HRMS (ESI) : C 15 H 29 The calculated value of O2 is 241.2162, and the measured value is 241.2161.

[0172] Example 31: Cell culture and treatment of cells with the compounds of the present invention Results

[0173]

[0174] To a stirred solution of compound 8 (187 mg, 0.78 mmol) in CH2Cl2 (5 ml) was added DIC (132.0 μl, 0.86 mmol) and DMAP (79 mg, 0.78 mmol), and the mixture was stirred for 30 minutes. Protected vitamin C 3 (418 mg, 1.17 mmol) in CH2Cl2 (5 ml) was added dropwise, and the reaction mixture was stirred at room temperature overnight and then filtered. The filtrate was concentrated under reduced pressure. The residue was purified by column chromatography using ethyl acetate - hexane (15%) to give compound 9 (290 mg, 64%). Compound 9: Colorless oil, Rf: 0.70 (20% ethyl acetate / hexane). IR (ATR, cm -1 ): 3404, 2953, 2919, 2850, 1761, 1742, 1671. MS (ESI) [m / z, (%)]: 579 ([M + +1], 100), 367 (34), 269 (84). HRMS (ESI): C 35 H 47 O7 calcd for 579.3316, found 579.3303.

[0175] Figures 1-12 furyl-2-hydroxyethyl ester (Compound I b ) Preparation

[0176]

[0177] To a mixture of compound 9 (44 mg, 0.07 mmol) in methanol (4 ml) was added a catalytic amount of Pd / C (10%), and the suspension was stirred at room temperature under H2 for 4 h. Then the mixture was filtered through Celite, and the filtrate was rotary evaporated to give I b (23 mg, 74%). Compound I b : Colorless oil, Rf: 0.09 (ethyl acetate). IR (ATR, cm -1 ): 3378, 2889, 2837, 1757. 11H-NMR (MeOD-d4, δ): 4.78 (m, 8H), 4.22 (m, 3H, CH2-1”, CH-2”), 2.41 (m, 2H, CH2-2), 1.78 (m, 4H), 1.55 (m, 4H), 1.19 (m, 14H), 0.92 (m, 3H, CH3-6’) ppm. 13 13C-NMR (MeOD-d4, δ): 174.1 (CO), 171.8 (CO), 152.6 (C-7”), 118.7 (C-6”), 75.8 (CH-3”), 66.7 (CH-2”), 64.4 (CH2-1”), 37.7 (CH-4 / 7), 37.3 (CH-4 / 7), 37.3 (CH2-2), 32.9 (CH2), 32.7 (CH2), 32.0 (CH2), 31.7 (CH2), 31.2 (CH2), 29.4 (CH2), 28.5 (CH2), 28.3 (CH2), 26.7 (CH2), 22.4 (CH2), 13.1 (CH3-6’) ppm. MS (ESI) [m / z, (%)]: 416 (100), 399 ([M + +1], 49), 367 (72), 282 (29). HRMS (ESI): C 21 H 35 The calculated value of C21H32O7 is 399.2377, and the measured value is 399.2372.

[0178] Figure 13

[0179] Cell culture

[0180] The BXPC3, CAPAN2, and RWP1 cell lines derived from human pancreatic cancer were provided by the Biomedical Research Institute (IRB) Barcelona; the MW115 and IGR39 cell lines derived from human primary melanoma and the MW266.4 and IGR37 derived from human metastatic melanoma were provided by Dr. Manel Esteller of the Catalan Institute of Oncology (ICO) Barcelona (Vizoso M. et al., Epigenetic activation of a cryptic TBC1D16 transcript enhances melanoma progression by targeting EGFR, Nat Med., 2015, Vol. 21(7), pp. 741-50); the DLDL1, SW480, and HCT116 cell lines derived from human colon cancer were provided by Dra. Neus Agell of the Research Institute August Pi Sunyer (IDIBAPS)-University of Barcelona (UB); the NUG-C4 and COLO668 cell lines derived from human gastric cancer and lung cancer were provided by the Center for Genomic Regulation (CRG) Barcelona, respectively. Human primary endothelial cells from umbilical cord (HUVEC) and aorta (HAEC) were obtained directly from the researcher Dra. Teresa Royo and stored in liquid nitrogen in the laboratory. The BXPC3, CAPAN2, and DLD1 cell lines were maintained in RPMI-1640 medium, SW480 and HCT116 were maintained in DMEM / HAM, RWP1 and all melanoma cell lines were maintained in DMEM and the cell culture medium (Gibco) was supplemented with 10% fetal bovine serum and antibiotics. The HUVEC and HAEC primary cells were maintained in M199 medium (Gibco) supplemented with 20% fetal bovine serum, endothelial cell growth supplement (ECGS), heparin (Hep), and antibiotics. The cultures were maintained in a cell culture incubator at 37 °C and a humidified atmosphere containing 5% CO2.

[0181] The different compounds to be tested were easily dissolved at a concentration of 0.5 M in 100% methanol, and then a 0.1 M intermediate dilution was prepared in 100% ethanol. In this latter dilution, different treatment solutions at established concentrations were prepared in the corresponding supplemented culture medium. The different treatment solutions were prepared at double concentrations, and 100 μl of the treatment solution was added to the same volume of cell growth medium in the wells to achieve the final concentrations (from 0.1 to 0.3 mM – 0.1, 0.2, 0.25, and 0.3 mM).

[0182] Cell treatment

[0183] The determination of the different compounds was carried out in 96-well plates according to the protocol explained below.

[0184] In the case of different human cancer cell lines, 0.5% trypsin-EDTA was used and in the case of human primary endothelial cells, 0.25% trypsin-EDTA was used, and the cells were resuspended by trypsin / EDTA digestion. After resuspension in the culture medium, they were counted in a Newbauer chamber after dilution 1:1 with trypan blue. This staining allows knowing the number of viable cells in the suspension. A suitable cell dilution was prepared according to the count (5000 or 10000 cells / 100 μl / well in 96-well plates, depending on the growth rate of different cell types). The cells were left in the cell culture incubator for 48 hours. After 48 hours of incubation, 100 μl / well of the double-concentration compound solution prepared as explained above was added. Then, the treatment was maintained for 72 hours by keeping the cells in the cell culture incubator.

[0185] After 72 hours, the culture medium was removed by pouring, the cells were washed twice with DPBS, and then the cells were fixed with 100 μl of 4% paraformaldehyde solution for 30 minutes. Then, two washes were carried out with 100 μl of mQ H2O, and immediately 50 μl of 0.25% crystal violet solution prepared in distilled water was added and maintained at room temperature for 30 minutes. At the end of the staining time, several washes were carried out with distilled water to completely remove the excess crystal violet, and then the plate was completely dried in an oven at 37 °C.

[0186] By Biotek Synergy TM 2 Multi-Detection Microplate Reader, the optical density value of each well was obtained using a 590 nm filter, and the average value of each well was obtained by scanning the readings.

[0187] ​

[0188] As can be observed in ​ When primary or metastatic human cancer cells from various different sources were treated with the compounds of the present invention at gradually increasing concentrations, the growth of the cancer cells was significantly reduced.

[0189] In addition, Compound I b showed remarkable inhibitory ability even at a concentration as low as 0.2 mM.

[0190] Notably, the administration of the compounds of the present invention did not significantly affect the growth of normal non-transformed cells. This lack of significant toxicity was independent of the dose of the peptide administered (in the range of 0.1 mM up to 0.3 mM, ​ ).

[0191] These results clearly demonstrate that the compounds of the present invention have high therapeutic potential as anti-cancer agents due to their low toxicity in non-transformed cells and high growth inhibitory activity in both primary and metastatic cancer cells.

[0192] Citation List

[0193] T.W. Greene and P.G.M. Wuts, Protective Groups in Organic Synthesis, Chapter 2, "Protection for the Hydroxyl Group, Including 1,2- and 1,3-Diols", John Wiley & Sons, Inc., 1999, pp. 17 - 245.

[0194] Vizoso M. et al., Epigenetic activation of a cryptic TBC1D16 transcript enhances melanoma progression by targeting EGFR, Nat Med., 2015, Vol. 21(7), pp. 741 - 50.

Claims

1. A compound of formula (I) or a pharmaceutically acceptable salt thereof, (I) wherein: n is 1 or 2; R1 is a divalent radical selected from CH2 or O; and R2 is C4-C9 alkyl.

2. The compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein n is 2.

3. The compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein R2 is C5 alkyl.

4. The compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein: n is 2; R1 is CH2; and R2 is C5 alkyl.

5. A pharmaceutical composition comprising a therapeutically effective amount of the compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-4, and at least one pharmaceutically acceptable excipient.

6. Use of the compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-4 for the preparation of a medicament for the treatment or prevention of a tumor disease, wherein the tumor disease is selected from pancreatic cancer, melanoma, colon cancer, gastric cancer and lung cancer.

7. The use according to claim 6, wherein the tumor disease is pancreatic cancer.

8. A process for preparing a compound of formula (I) according to claim 1, which comprises: a) subjecting a compound of formula (II) to an esterification reaction with a compound of formula (III), and b) deprotecting the compound obtained from a); wherein: n is 1 or 2; R1 is a divalent radical selected from CH2 or O; R2 is C4-C9 alkyl; and PG is a hydroxyl protecting group, 。

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