Synthesis of HMO Propionate The present invention relates to specific propionate compounds and to a new and improved synthesis of specific propionates as well to their application. Propionate compounds are very useful compounds, either as such or as intermediates in organic synthesis, or nutrition and food preservation. It is known that propionate is a major microbial fermentation metabolite in the human gut with putative health effects that extend beyond the gut epithelium. Propionate is thought to lower lipogenesis, serum cholesterol levels, and carcinogenesis in other tissues. Steering microbial propionate production through diet could therefore be a potent strategy to increase health effects from microbial carbohydrate fermentation. The present review first discusses the two main propionate-production pathways and provides an extended gene-based list of microorganisms with the potential to produce propionate. Second, it evaluates the promising potential of arabinoxylan, polydextrose, and L-rhamnose to act as substrates to increase microbial propionate. Furthermore, given the complexity of the gut microbiota, propionate production is approached from a microbial-ecological perspective that includes interaction processes such as cross- feeding mechanisms. Finally, it introduces the development of functional gene-based analytical tools to detect and characterize propionate-producing microorganisms in a complex community. The information in this review may be helpful for designing functional food strategies that aim to promote propionate-associated health benefits Propionate is thought to lower lipogenesis, serum cholesterol levels, and carcinogenesis in other tissues. Steering microbial propionate production through diet could therefore be a potent strategy to increase health effects from microbial carbohydrate fermentation. Due to the importance of propionates, the goal of the present invention was to provide a way to produce propionate compounds having all advantages in a good yield. Surprisingly, it was found that specific propionate compounds as defined by the formula below can be obtained in good yields and selectivities by a new and easy process. Therefore, the present invention relates to a process (P) for producing a compound of formula (I) , wherein R, R ₁ , R _2, R ₃ , R ₄ R ₅ , R ₆ R ₇ , R ₈ and R ₉ are either H or , with the proviso that less than 5 substituents are H, characterised in that a compound of formula (II) is reacted with a compound of formula (III) wherein X is a halogen atom, -OH or the following moiety (* marks the bond to the CO group). Preferably, the process according to the present invention relates to a process for producing a compound of formula (I) , wherein R, R1, R2, R3, R4 R5, R6 R7, R8 and R9 are either with the proviso that less than 4 substituents are H. (more preferably less than 3 substituents are H, even more preferably less than 2 substituents are H, more preferably none of the substituents are H). Therefore, the present invention relates to a process (P1), which is process (P), wherein the compound of formula (I) less than 4 substituents are H. Therefore, the present invention relates to a process (P1’), which is process (P), wherein the compound of formula (I) less than 3 substituents are H. Therefore, the present invention relates to a process (P1’’), which is process (P), wherein the compound of formula (I) less than 2 substituents are H. Therefore, the present invention relates to a process (P1’’’), which is process (P), wherein the compound of formula (I) none of the substituents are H. It is clear that it is possible to get mixtures of compounds of formula (I), which have a different substitution pattern. In the following the process according to the present invention is discussed and described in more detail. As stated above the starting material is the compound of formula (II) . This compound is known as 2'-Fucosyllactose (2’-FL). 2’-FL is a human milk oligosaccharide (HMO). Human milk oligosaccharides (HMOs) are a family of structurally diverse unconjugated glycans that are highly abundant in and unique to human milk. Originally, HMOs were proposed to be prebiotic "bifidus factors," or human milk glycans found to promote growth in Bifidobacterial species of the gut and found uniquely in the stool of breast- fed infants compared to formula fed infants. Furthermore, 2’-FL has a positive influence on short-chain fatty acids in the gut. 2’-FL can be isolated or synthesized. Alternatively, it is also available commercially from a variety of suppliers. 2’-FL is reacted with a compound of formula (III) wherein X is a halogen atom, -OH or the following moiety (* marks the bond to the CO group). Preferably More preferably the compound of formula (IIIa) is used. Therefore, the present invention relates to a process (P2), which is the process (P), (P1), (P1’), (P1’’) or (P1’’’), wherein the 2’-FL is reacted with a compound of formula (III) wherein X is a halogen atom, -OH or the following moiety (* marks the bond to the CO group). Therefore, the present invention relates to a process (P2’), which is the process (P), (P1), (P1’), (P1’’) or (P1’’’), wherein the 2’-FL is reacted with a compound of formula (III) wherein X is a -Cl, -OH or the following moiety (* marks the bond to the CO group). Therefore, the present invention relates to a process (P2’’), which is the process (P), (P1), (P1’), (P1’’) or (P1’’’), wherein the 2’-FL is reacted with a compound of formula (IIIa) . Usually and preferably, the process according to the present invention is carried out in the presence of at least one polar, basic, inert solvent. Such a solvent is usually chosen from the group consisting of pyridines, such as pyridine, substituted pyridines such as dimethyl aminopyridines, or methyl pyridines, or trialkylamines such as triethylamine, diisopropylethylamine, or tributylamine. Therefore, the present invention relates to a process (P3), which is the process (P), (P1), (P1’), (P1’’), (P1’’’), (P2), (P2’) or (P2’’), wherein the reaction is carried out in the presence of at least one polar, basic, inert solvent. Therefore, the present invention relates to a process (P3’), which is the process (P3), wherein the at least one polar, basic, inert solvent is chosen from the group consisting of pyridines, substituted pyridines and trialkylamines. Therefore, the present invention relates to a process (P3’’), which is the process (P3), wherein the at least one polar, basic, inert solvent is chosen from the group consisting of pyridines, dimethyl aminopyridines, methyl pyridines, triethylamine, diisopropylethylamine and tributylamine. The solvent is used in molar excess in view of the compound of formula (II). The amount of the solvent is not critical for the process according to the present invention. Therefore, the present invention relates to a process (P4), which is the process (P), (P1), (P1’), (P1’’), (P1’’’), (P2), (P2’), (P2’’), (P3), (P3’) or (P3’’), wherein the solvent is used in molar excess in view of the compound of formula (II). The compound of formula (III) needs to be added in such an amount that all (or at least 6 positions) of the compound of formula (II) are propionated. Usually the compound of formula (III) is used in a molar ratio regarding compound of formula (II) of 6:1 to 100 (preferably 10:1 to 100:1). Therefore, the present invention relates to a process (P5), which is the process (P), (P1), (P1’), (P1’’), (P1’’’), (P2), (P2’), (P2’’), (P3), (P3’), (P3’’) or (P4), wherein the compound of formula (III) is used in a molar ratio in regard to compound of formula (II) of 6:1 to 100. Therefore, the present invention relates to a process (P5’), which is the process (P), (P1), (P1’), (P1’’), (P1’’’), (P2), (P2’), (P2’’), (P3), (P3’), (P3’’) or (P4), wherein the compound of formula (III) is used in a molar ratio in regard to compound of formula (II) of 10:1 to 100:1. Furthermore, the process of the present invention can be carried out in a mixture of organic and inorganic bases. Organic bases are i.e., pyridines, such as pyridine; substituted pyridines such as dimethyl aminopyridines, or methyl pyridines; or trialkylamines such as triethylamine, diisopropylethylamine, or tributylamine. Inorganic bases are i.e., carbonates, such as potassium or sodium carbonate and the corresponding hydrogen carbonates. Therefore, the present invention relates to a process (P6), which is process (P), (P1), (P1’), (P1’’), (P1’’’), (P2), (P2’), (P2’’), (P3), (P3’), (P3’’), (P4), (P5) or (P5’), wherein the reaction is carried in a mixture of at least one organic base and at least one inorganic base. Therefore, the present invention relates to a process (P6’), which is process (P6), wherein the at least one organic base is chosen from the group consisting of pyridines, substituted pyridines and trialkylamines. Therefore, the present invention relates to a process (P6’’), which is process (P6), wherein the at least one organic base is chosen from the group consisting of pyridine, dimethyl aminopyridines, methyl pyridines, triethylamine, diisopropylethylamine and tributylamine. Therefore, the present invention relates to a process (P6’’’), which is process (P6), wherein the at least one inorganic base is chosen from the group consisting of carbonates and the corresponding hydrogen carbonates. Therefore, the present invention relates to a process (P6’’’’), which is process (P6), wherein the at least one inorganic base is chosen from potassium carbonate, sodium carbonate and the corresponding hydrogen carbonates. Usually and preferably, the reaction is carried out at a temperature of between 15–50° C (more preferably at a temperature of between 20–30° C). Therefore, the present invention relates to a process (P7), which is process (P), (P1), (P1’), (P1’’), (P1’’’), (P2), (P2’), (P2’’), (P3), (P3’), (P3’’), (P4), (P5), (P5’), (P6), (P6’), (P6’’), (P6’’’) or (P6’’’’), wherein the reaction is carried out at a temperature of 15 – 50° C. Therefore, the present invention relates to a process (P7’), which is process (P), (P1), (P1’), (P1’’), (P1’’’), (P2), (P2’), (P2’’), (P3), (P3’), (P3’’), (P4), (P5), (P5’), (P6), (P6’), (P6’’), (P6’’’) or (P6’’’’), wherein the reaction is carried out at a temperature of 20–30° C. The isolation of the reaction compound (compound of formula (I)) is carried by using commonly known methods. Furthermore, the reaction product of step (i) can be purified. This is also done by commonly known and used methods. Furthermore, the compounds of formula (I) are new. Therefore, the present invention relates to compounds of formula (I) , wherein R, R ₁ , R _2, R ₃ , R ₄ R ₅ , R ₆ R ₇ , R ₈ and R ₉ are either with the proviso that less than 4 substituents are H. (more preferably less than 3 substituents are H, even more less than 2 substituents are H, more preferably wherein none of the substituents are H). The following examples illustrate the invention further without limiting it. All percentages and parts, which are given, are related to the weight and the temperatures are given in °C, and the pressures are absolute pressures when not otherwise stated. Examples Example 1: Synthesis of 2'-FL perpropionate 2'-Fucosyllactose (1.14 g, 2.33 mmol) was placed in a 100 mL 3-necked round-bottom flask under an argon atmosphere. A mixture of pyridine (20.7 ml, 256 mmol) and propionic acid anhydride (18.0 ml, 107 mmol) was added in one portion. The resulting white turbid mixture was stirred overnight at room temperature. The reaction mixture was concentrated under reduced pressure. The residue was diluted in dichloromethane and extracted several times with a total 125 of sat. aq. mL NaHCO3 and once with brine, dried with magnesium sulfate, filtered, and concentrated under reduced pressure. To the residue were added 50 mL of sat. aq. NaHCO3 and the mixture was stirred overnight to hydrolyze excess propionic acid. It was then extracted several times with dichloromethane. The combined organic layers were washed with brine, dried with magnesium sulfate, filtered, and concentrated to give 0.790 g of a colorless solid. The crude product was purified by chromatography (SiO2, 40-60 micrometer, heptane/ethyl acetate, detected with ELSD). The product was characterized by ¹ H-, ¹³ C-NMR spectroscopy, IR-spectroscopy and MS (high resolution). Yield: 29%.