Method for synthesizing delta-decalactone

Abstract

The invention discloses a method for synthesizing delta-decalactone, which comprises the following steps of: (1) performing aldol condensation reaction on cyclopentanone and valeraldehyde which are taken as initial raw materials by taking polyethylene glycol 400 (PEG-400) as a phase transfer catalyst under the alkaline condition, and dehydrating under the action of an acid catalyst to obtain 2-pentene cyclopentanone; (2) performing normal pressure catalytic hydrogenation on the 2-pentene cyclopentanone by taking palladium-carried ion exchange resin as a catalyst and methanol as a solvent to obtain 2-pentyl cyclopentanone; and (3) performing Baeyer-villiger rearrangement reaction on the 2-pentyl cyclopentanone by taking methanol as a solvent and acid as a catalyst in a new reaction system adopting hydrogen peroxide for direct oxidation to synthesize crude delta-decalactone, and treating the crude delta-decalactone by using a vacuum thin-film distillation device with shorter retention time to obtain the high-purity product. The method is feasible, and is easy and convenient to implement; the raw materials are readily available, and wide in sources; the yield is high; the yield of the product of delta-decalactone is increased, and the purity of the delta-decalactone is greatly improved; and the catalysts can be repeatedly used, and have great application value.

Description

technical field [0001] The invention relates to the technical field of synthesis of δ-lactone, more specifically to a method for synthesizing δ-decalactone. The product δ-decalactone of the present invention is a compound with a very strong, sweet, nutty aroma, and when the concentration is below 0.1%, it has a sweet, creamy mild aroma after dilution. It is used as a modifier of γ-decalactone and other internal compounds in milk and cream food flavors. In addition, δ-decalactone acts as a modifier when used in the blending of cosmetic essences such as tuberose and other cosmetics. Background technique [0002] Lactone is an important organic compound and intermediate, and has broad application prospects in the fields of fragrance, flavor and drug synthesis. For example, γ- and δ-lactones have been used in high-grade cosmetics, food and tobacco industries, etc., and because lactones are the main components of natural cream flavor, and natural cream contains a lot of animal ...

AI Technical Summary

Problems solved by technology

[0003] There are many reports at home and abroad about the synthetic method of δ-lactone. According to its synthetic route, there are mainly the following three methods in combination: one is to react with cyclohexanedione and bromo-n-hexane, and then oxidize and open the ring , reduction and cyclization to obtain δ-decalactone, the synthesis process of this method is more loaded down with trivial details, and the yield is lower; the second is to carry out Dieckmann condensation with diethyl glutarate, and then use anhydrous K 2 CO 3 React with bromo-n-heptane in acetone, deacidify and oxidize to obtain δ-decalactone. This method has reasonable cost, but the steps are long and the yield is not high, so it is difficult to apply to industrial production; the third is to use n-pentyl Aldehyde is condensed with cyclopentanone, then reduced by hydrogenation, and oxidized to δ-lactone. This method has a short synthesis route and requires catalytic hydrogenation reaction, which is difficult for industrial production.