121468-66-4

Upstream product

• 29606-79-9 p-menth-8-en-3-one 
• 106-23-0 3,7-dimethyl-oct-6-enal 
• 50-00-0 formaldehyd 
• 2385-77-5 (R)-Citronellal 
• 5392-40-5 (E/Z)-3,7-dimethyl-2,6-octadienal 
• 17882-43-8 (?)-trans-isopulegone 
• 108-24-7 acetic anhydride 
• 1192-37-6 methylenecyclohexane 
• 130628-58-9 Dec-9-enylmagnesium bromide 
• 89-82-7 pulegone 
• 29606-79-9 isopulegone 
• 5949-05-3 (S)-Citronellal 
• 16750-82-6 (S)-isopiperitenone 
• 5989-27-5 D-limonene 

Downstream Products

• 38049-01-3 2-((1R,2R,4S)-2-Hydroxy-4-methyl-cyclohexyl)-propenal 
• 117861-57-1 Acetic acid (2R,3R,4S,5R,6R)-3,5-diacetoxy-2-acetoxymethyl-6-(2-isopropenyl-5-methyl-cyclohexyloxy)-tetrahydro-pyran-4-yl ester 
• 89-79-2 (rac)-neo-isopulegol 
• 13834-14-5 (+/-)-(1RS,3SR,4SR)-p-menth-8⁽¹⁰⁾-ene-ane-3,9-diol 
• 38049-01-3 2-((1R,2S,4S)-2-Hydroxy-4-methyl-cyclohexyl)-propenal 
• 106-23-0 3,7-dimethyl-oct-6-enal 
• 141-26-4 3,7-dimethyl-7-octenal 
• 135594-71-7 3-phenylisopulegol 
• 57576-09-7 (1R,2S,5R)-5-methyl-2-(prop-1-en-2-yl)cyclohexyl acetate 

Relevant academic research and scientific papers

Environment friendly organic synthesis using bismuth compounds. An efficient method for carbonyl-ene reactions catalyzed by bismuth triflate

Bismuth triflate (0.1 mol %) is a highly efficient catalyst for the cyclization of citronellal 1, a reaction that yields a ratio of 80:20 of isopulegol 2 and neoisopulegol 3. This methodology has also been extended to the synthesis of substituted piperidines. The bismuth triflate catalyzed ene reaction of aldehyde 4 gives a 70:30 mixture of piperidines 5 and 6. The advantages of these methods include the use of a highly efficient catalyst that is relatively nontoxic, cheap and easy to handle.

Continuous synthesis of menthol from citronellal and citral over Ni-beta-zeolite-sepiolite composite catalyst

One-pot continuous synthesis of menthols both from citronellal and citral was investigated over 5 wt% Ni supported on H-Beta-38-sepiolite composite catalyst at 60–70 °C under 10–29 bar hydrogen pressure. A relatively high menthols yield of 53% and 49% and stereoselectivity to menthol of 71–76% and 72–74% were obtained from citronellal and citral respectively at the contact time 4.2 min, 70 °C and 20 bar. Citral conversion noticeably decreased with time-on-stream under 10 and 15 bar of hydrogen pressure accompanied by accumulation of citronellal, the primary hydrogenation product of citral, practically not affecting selectivity to menthol. A substantial amount of defuctionalization products observed during citral conversion, especially at the beginning of the reaction (ca. 1 h), indicated that all intermediates could contribute to formation of menthanes. Ni/H-Beta-38-sepiolite composite material prepared by extrusion was characterized by TEM, SEM, XPS, XRD, ICP-OES, N2 physisorption and FTIR techniques to perceive the interrelation between the physico-chemical and catalytic properties.

Method for preparing L-menthol by adopting modified homogeneous catalyst

The invention discloses a method for preparing L-menthol by adopting a modified homogeneous catalyst. The method comprises the following steps: preparing a modified homogeneous catalyst, preparing isopulegol, preparing D, L-menthol, and preparing L-menthol; wherein a ligand is prepared from 2, 6-dimethylpyridine and a ketone compound by using the modified homogeneous catalyst, the ligand is reacted with alkyl aluminum to obtain an organic aluminum compound, and L-menthol is prepared by chemically inducing chiral resolution of D, L-menthol. According to the method, the organic aluminum compoundis used as the catalyst of the ring-closure reaction of citronellal, so that the yield of isopulegol is increased, the selectivity on product isopulegol is high, and the used organic aluminum catalyst is easy to synthesize, high in stereoselectivity to reaction and easy to crystallize and recover; D, L-menthol is split by a chemical induction method, the method is simple to operate, the reactionyield of each step is high, the reaction conditions are stable, the product cannot be partially racemized, and the product loss is small.

Nb-doped variants of high surface aluminium fluoride: A very strong bi-acidic solid catalyst

A niobium doped high surface aluminium fluoride (HS-AlF3) catalyst was prepared, using an approach in which niobium doped aluminium hydroxide fluoride obtained via reaction of aqueous HF with the respective metal alkoxides in isopropanol is further fluorinated under flow of CHClF2 at 200 °C. A comparable procedure was used to synthesize a Nb-free variant for comparison. Both catalysts exhibit very strong Lewis acidic surface sites which are capable to activate strong carbon-halogen bonds at room temperature, just as the classical high-surface AlF3 (HS-AlF3), obtained by reacting aluminium isopropoxide with anhydrous HF, does. The catalysts were characterized by elemental analysis, P-XRD, MAS NMR spectroscopy, N2 adsorption, NH3-TPD, and pyridine photoacoustic FT-IR spectroscopy. In contrast to previously reported niobium doped HS-AlF3, which was prepared using anhydrous HF, the doped catalyst obtained via this aqueous HF-route shows excellent performance both in the isomerization of 1,2-dibromohexafluoropropane, a reaction that occurs only in the presence of the strongest Lewis acids, and in the cyclization of citronellal to isopulegol, a reaction which requires both, Lewis and Br?nsted acid sites.

Unveiling reactive metal sites in a Pd pincer MOF: Insights into Lewis acid and pore selective catalysis

A porous Zr metal-organic framework, 1-PdBF4 [Zr6O4(OH)4(OAc)2.4{(PNNNP)Pd(MeCN)}2.4(BF4)2.4; PNNNP = 2,6-(HNPAr2)2C5H3N; Ar = p-C6H4CO2-], has been synthesized via postsynthetic oxidative I-/BF4- ligand exchange using NOBF4. 1-PdBF4 enjoys markedly superior catalytic activity and recyclability to its trifluoracetate-exchanged analogue, 1-PdTFA, for the intramolecular cyclization of o-alkynyl anilines and the carbonyl-ene cyclization of citronellal. Moreover, 1-PdBF4 demonstrates a rare example of pore selective catalysis for the cyclization of 2-ethynyl aniline.

One-Pot Absolute Stereochemical Identification of Alcohols via Guanidinium Sulfate Crystallization

A novel technique for the absolute stereochemical determination of alcohols has been developed that uses crystallization of guanidinium salts of organosulfates. The simple one-pot, two-step process leverages facile formation of guandinium organosulfate single crystals for the straightforward determination of the absolute stereochemistry of enantiopure alcohols by means of X-ray crystallography. The strong hydrogen bonding network drives the stability of the crystal lattice and allows for a diverse range of organic alcohol substrates to be analyzed.

Method for improving optical purity of L-isopulegol through chiral resolution

The invention provides a method for improving the optical purity of L-isopulegol through chiral resolution. The method comprises the following steps: putting D,L-isopulegol and a resolution agent L-linalool into a dispersant and an auxiliary agent and reacting for 3 to 4 hours at 70 to 80 DEG C; after cooling to 10 to 25 DEG C, centrifuging and separating to obtain an intermediate L-isopulegol.L-linalool; carrying out alkali analysis on the intermediate; decomposing the intermediate; then carrying out gel chromatography to obtain the high-purity L-isopulegol. The method has the advantages of low raw material cost and low reaction energy consumption and is applicable to large-scale industrialized production.

Citronellal cyclisation over heteropoly acid supported on modified montmorillonite catalyst: effects of acidity and pore structure on catalytic activity

Citronellal cyclisation to isopulegol is an important intermediate step in the production of menthol. Several heteropoly acids (PTA) supported on modified montmorillonite (MM) catalysts were synthesized and then tested in cyclisation reactions. The prepared samples were characterized by XRD, ICP-OES, FTIR, N2 sorption, NH3-TPD, pyridine adsorption, amine titration and FE-SEM techniques. Effects of post-treatment were studied on montmorillonite pore structure, acidity and catalytic activity. The catalytic activity and isopulegol selectivity improved with acid-treatment and PTA loading. The amount of Lewis acidity of montmorillonite was enhanced with acid-treatment and PTA impregnation. In cyclisation, highest catalytic activity (31.87?mmol?cat?g?1?min?1) was achieved with 96% isopulegol yield in the use of 20% PTA-MM catalyst. The highest catalytic activity and selectivity were obtained in the presence of higher acidity and strong Lewis acidic sites, whereas effects of pore structure blockage seemed minor. The catalytic activity further decreased with the loss of active acidic sites (L and B) due to PTA decomposition with calcination at a higher temperature.

Method of preparing isopulegol from citronellal and method of recycling catalyst therein

The invention provides a method of preparing isopulegol from citronellal and a method of recycling a catalyst therein. Citronellal is used as an initial material to prepare isopulegol under the catalytic action of a binaphthol-based aluminum compound via cyclization; a high-boiling-point solvent is used to recycle the catalyst. The binaphthol-based aluminum compound is used as the catalyst; the conditions are milder; reaction enantioselectivity is 95-99.9%, and the conversion rate is up to 95-99.9%. The method of recycling the catalyst is simple; the recycled catalyst is directly usable, and no regeneration is required; the methods are particularly suitable for industrial production.

Preparation method of isopulegol

The invention belongs to the technical field of chemistry and chemical engineering, and relates to a preparation method of isopulegol. The preparation method is characterized in that citronellal is used as raw materials; under the catalysis of anhydrous zinc bromide, a proper quantity of calixarene is added as a cocatalyst; cyclization reaction is performed to generate the isopulegol; zinc bromidecatalyst containing wastewater generated after the quenching reaction of 0.05mol/l of hydrobromic acid water solution is subjected to azeotropic dehydration to prepare anhydrous zinc bromide again tobe applied to cyclization reaction. The method has the advantages that the cyclization efficiency is greatly improved; meanwhile, wastewater and waste salt are greatly reduced; the green synthesis ofthe isopulegol is realized. The operation is simple and convenient; the process design is ingenious; the environment pollution is low; the preparation method is suitable for industrial production.