Chrysanthemum acid resolution can obtain right-handed body and left-handed body. The first use of quinic acid to split racemic cis-chrysanthemum acid and racemic trans-chrysanthemum acid to obtain pure optically active chrysanthemum acid, and later use Su-1-p-nitrophenyl-N,N-dimethylamino -1, 3-propanediol as the resolution agent, isopropyl ether and methanol or toluene and methanol as the mixed solvent, the racemic trans chrysanthemum acid was resolved, in addition, there are also α-methylbenzylamine, 1-phenyl-2-(p-methylphenyl) ethylamine (PTE for short), L-lysine, 1-α-naphthylamine and D(-)-Phenylglycine is used as a splitting agent.
Using (±) trans-chrysanthemum acid resolution, D-trans-chrysanthemum acid (1R, 3R-chrysanthemum acid) and L-trans-chrysanthemum acid (1S, 3S-chrysanthemum acid) can be obtained respectively. The process is as follows.
(±) trans-chrysanthemum acid, D-(-) su-type p-nitrophenyl-2-N,N-dimethylamino -1, 3-propanediol are used as splitting agents, and the mixed solution of toluene and methanol is used as solvent. Put it into a reaction kettle, stir evenly, freeze and crystallize until -5 ℃, crystallize completely, filter, acid wash with appropriate amount of 15% hydrochloric acid, separate out the water layer, the crude D-trans chrysanthemum acid was obtained, distilled under reduced pressure, the refined D-trans chrysanthemum acid was collected at 130 ℃/130Pa fraction, and then the filter cake was washed with metered 15% hydrochloric acid, extracted with toluene, separated into water layer, and dissolved to obtain L-trans chrysanthemum acid. The acidic water layer was neutralized with alkali, and the D-(-) splitting agent solid was filtered out, washed, dried.
Domestic L-() Su-type p-nitrophenyl-2-N,N-dimethylamino -1,3-propanediol is used as the resolution agent, and (±) trans-chrysanthemum acid is separated to be rich in dextrotrans-chrysanthemum acid and L-trans chrysanthemum acid, respectively, which are applied in industrialization.
1R, 3R-chrysanthemum acid can also be obtained by using () 1-phenyl-2-(p-methylphenyl) ethylamine as a resolution agent.