Gamma-Decalactone CAS 706-14-9

During the reaction, the double bond position is transferred from the chain to the β, γ position, and then the lactonization occurs. The co-thermal reaction of ω-decenoic acid and sulfuric acid will generate more by-products during the reaction process, so the reaction yield is low, and the by-products are many, the reaction selectivity is also relatively low, and the efficiency is relatively low. , and this route uses sulfuric acid as a catalyst, once a large-scale production is formed, a large number of three wastes will be generated in the follow-up treatment;

Using metal or corresponding acetate as oxidant, a large amount of heavy metal-containing waste water is generated after the reaction. Considering from the perspectives of green chemistry and environmental protection, this route requires high cost, which is not conducive to large-scale process production.

Condensation of a carbonyl compound (octanal) and β-halogenated ester (β-bromopropionate) in the presence of zinc yields β-hydroxyester, which is then dehydrated under acid catalysis to generate the corresponding Gamma-Decalactone. Organozinc reagents are used in the synthesis process and must be reacted in an inert solvent, and further research is needed to realize industrialization.

GDL enzymes have catalytic activity in the non-aqueous phase and are widely used in organic synthesis. Among them, lipase is the most widely used, which is cheap, does not require coenzyme, and has strong substrate adaptability. Lipases can not only catalyze the hydrolysis of lipids, but also catalyze esterification and transesterification reactions in the organic phase, including the formation of lactones from hydroxy fatty acids. It is very difficult to cyclize these hydroxy acids by conventional methods, and the yield is very low. It is much easier to complete the cyclization process in an organic medium by an enzymatic method, which undoubtedly provides a large-scale marketization of such flavor lactones. good way. Sometimes other enzymatic methods of biotechnology can also be used when conditions permit. Perhaps in the near future, it will also become one of the important means to solve the problem of the marketization of lactone bioactive substances.

Using n-heptanol to carry out radical addition reaction with acrylic acid or methyl acrylate in the presence of a free radical initiator to prepare propyl-decalactone, which is the synthesis route of propyl-decalactone that can form large-scale production at present. Using n-heptanol and acrylic acid as starting materials, using di-tert-butyl peroxide as an initiator, adding a reaction solvent, firstly adopting a “one-pot cooking” method, free radical addition to synthesize the crude product of gamma-decalactone, and distillation to recover the reaction Solvent, then prepare gamma-decalactone by rectifying and purifying, in this synthesis process, the by-product cannot be separated from the reaction system in time, cause the reaction yield to drop, the reaction time is prolonged, and the product contains low-boiling impurities. Grease odor, high boiling impurities and poor oil consumption of isomers affect the final product aroma quality of Gamma-Decalactone.

CN201810882253.4 overcomes the common problems of complex separation and purification process, high energy consumption, low reaction yield, and unpurified product aroma quality in existing synthetic methods for gamma-decalactone, and provides a simple process and high reaction yield , the reaction speed is fast, the overall cost is relatively low, it is beneficial to form industrialized scale production, and is easy to realize the synthetic method of the gamma-decalactone synthetic fragrance of product serialization.

A method for synthesizing Gamma-Decalactone synthetic fragrance by reactive distillation, it is characterized in that: may further comprise the steps:

(a) 120g of heptanol, 90g of Gamma-Decalactone, 1g of catalyst sodium borohydride and 15g of initiator di-tert-butyl peroxide are added to the 500mL there-necked flask according to the proportion of ingredients, and the electromagnetic stirrer and the heat and cold exchange integrated machine are turned on, Keep the temperature at 20±5°C to obtain the batching mixture;

(b) take by weighing 360g heptanol again, join in the 1500mL heater of reactive distillation column, open electromagnetic stirrer and cold and heat exchange integrated machine, the temperature of heater is raised to 115～175 ℃ and insulation, then by The batching mixture in the step (a) is fed into the reaction zone of the reactive distillation column by a dripping pump; the temperature of the heater is controlled to be 145-175° C. during the dripping, and the dripping time is controlled to be 2-4h;

(c) open the tower top condensed water of reactive rectifying tower, separate out by-product tert-butanol and methyl alcohol from the tower top of reactive rectifying tower, separate out excess unreacted heptyl alcohol from the rectifying section side line of reactive rectifying tower Alcohol, the Gamma-Decalactone crude product is separated from the column bottom;

(d) transfer the Gamma-Decalactone crude product of step (c) into the rotary evaporator, open the cold and heat exchange integrated machine connected with the rotary evaporator, open the low vacuum, the control temperature is 95～125 ℃, and the rotational speed is 50～ 160r/min, pressure is 6667～10000Pa, collect low boiling point impurities and residual heptanol;

Then, the temperature is controlled to be 115-155° C., the rotational speed is 50-160 r/min, and the pressure condition is 3333-6667 Pa, and the gamma-decalactone is collected by collection.