Preparation method of chiral gamma-decalactone

Abstract

The invention discloses a preparation method of chiral gamma-decalactone. The method comprises the following steps that (1) racemic gamma-decalactone is subjected to loop opening by an inorganic alkali solution to obtain a gamma-hydroxy acid and alkali metal saline solution; then, an organic solvent is added; the PH value is regulated to a weak acid state by inorganic acid, so that generated gamma-hydroxy acid enters an organic phase; the separated organic phase is dried; (2) (S)-(-)-alpha-phenylethylamine is added into the organic phase; crystallization is performed to separate out gamma-hydroxy acid (S)-(-)-alpha-phenylethylamine salt with optical activity; (3) obtained amine salt is added into water; stirring, dissolution, crystallization and filtering are performed; after filter cake is added with water to be dissolved, inorganic acid is added; after acidification cyclization, an organic solvent is added for extraction to obtain (R)-(+)-gamma-decalactone; (4) inorganic acid is added into crystallization mother liquid in the steps (2) and (3) for further acidizing treatment; the organic solvent is used for extraction to obtain (S)-(-)-gamma-decalactone. When the preparation method is used, the operation is easy; two kinds of configuration of chiral gamma-decalactone can be obtained; the fragrance is pure, the advantages of high-half-quantity yield, high enantiomer excess values and low cost are realized.

Description

technical field

[0001] The invention relates to a preparation method of chiral lactone, in particular to a preparation method of chiral γ-decalactone. Background technique

[0002] Gamma-decalactone (4-hexylbutyrolactone) occurs naturally in fruits such as peaches, almonds, and strawberries. It has a strong fruity aroma and peach aroma when diluted. It is mainly used in the preparation of food, soap, daily cosmetic essence, and can also be used as a margarine flavor enhancer.

[0003] The aroma of (S)-(-)-γ-decalactone is soft, sweet coconut milk, with obvious fat color, with fruity, banana, lactone and jasmine-like top notes. The main aroma is very close to the raceme, but the aroma is fuller, the sweet and floral aroma is weaker, but the aroma is stronger and the lactone aroma is more obvious. Its specific rotation: [α] D 20 =-48.1° (c=1.5~2.5, CH 3 OH).

[0004] (R)-(+)-γ-Decalactone has an intense, fat-sweet fruity, coconut-like, caramel flavor. Very suitable for...