21758-30-5

Upstream product

• 2216-51-5 (-)-menthol 
• 79-43-6 dichloro-acetic acid 
• 79-36-7 dichloroacethyl chloride 

Downstream Products

• 147027-10-9 (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl (2R,5S)-5-(4-amino-2-oxo-1,2-dihydro-1-pyrimidinyl)-1,3-oxathiolane-2-carboxylate 
• 26315-61-7 L-menthyl glyoxylate 
• 147126-62-3 (2R,5R)-5-hydroxy-1,3-oxathiolane-2-carboxylic acid (1R,2S,5R)-5-methyl-2-isopropylcyclohexyl ester 
• 764659-72-5 (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl (2R,5S)-5-(4-amino-5-fluoro-2-oxo-1,2-dihydro-1-pyrimidinyl)-1,3-oxathiolane-2-carboxylate 

Relevant academic research and scientific papers

Emtricitabine synthesis method

The invention provides an emtricitabine synthesis method, which comprises: carrying out condensation on cheap and easily available dihaloacetic acid as a raw material and L-menthol, hydrolyzing to obtain menthyl glyoxylate hydrate, condensing with 2,5-dihydroxy-1,4-dithiane, carrying out halogenation, coupling with silylated 5-flucytosine, reducing, carrying out salt forming with salicylic acid toobtain emtricitabine salicylate, and finally re-crystallizing to obtain optically pure emtricitabine. According to the present invention, the whole synthesis process has characteristics of inexpensive and easily available raw materials, simple synthesis process and mild synthesis conditions, such that the synthesis cost of emtricitabine is substantially reduced; various raw materials have characteristics of good reaction selectivity and high utilization rate, such that the yield of the obtained emtricitabine is high; and the chiral substrate is easily removed during the synthesis, and the generated three-waste pollutants are less, such that the method is suitable for industrial large-scale production of emtricitabine.

Synthetic method for lamivudine

The invention provides a synthetic method for lamivudine. The synthetic method comprises the following steps: cheap easily-available dihaloacetic acid is used as a raw material, the dihaloacetic acidand L-menthol are subjected to condensation, hydrolysis is performed to obtain menthyl glyoxylate, the menthyl glyoxylate and 2,5-dihydroxy-1,4-dithiane are subjected to condensation, halogenation isperformed, the halogenated product and silanized cytosine are subjected to coupling, reduction is performed, the reduced product and salicylic acid are subjected to salt formation to obtain the a salicylate, and finally recrystallization is performed to obtain the optically-pure lamivudine. According to the method provided by the invention, the raw materials used in the whole synthetic process arecheap and easy to obtain, the synthetic process is simple, the synthetic conditions are mild, so that the synthetic costs of the lamivudine are greatly reduced; the raw material utilization rate andreaction selectivity are high, so that the yield of the obtained lamivudine is higher; and at the same time, a chiral substrate is easily removed during the synthesis, three waste (waste water, wastegas and solid waste) generated in the method are less, and the method is suitable for industrialized large-scale production of the lamivudine.

Structure of Enantiomeric Menthyl (Z)-2-Chloro-3-(4-nitrophenyl)oxirane-2-carboxylates and Full Assignment of Their NMR Spectra

The major products of the Darzan condensation of (-)- and (+)-menthyl dichloroacetates with p-nitrobenzaldehyde are menthyl (Z)-2-chloro-3-(4-nitrophenyl)oxirane-2-carboxylates; the (2S,3S)-(-)- and (2R,3R)-(+)-menthyl enanthiomers were isolated.

SYNTHESIS OF THIOALDEHYDES HAVING OPTICALLY ACTIVE ALKOXY MOIETY AND THEIR ASYMMETRIC HETERO DIELS-ALDER REACTION

Optically active α-alkoxycarbonylthioaldehydes (2a-g) were prepared using 8-arylmenthols as chiral auxiliaries.Their asymmetric hetero Diels-Alder reactions with cyclopentadiene gave the endo cycloadducts (3 and 4) and exo cycloadducts (5 and 6) with moderate diastereomeric excesses.However, the major endo cycloadducts (3b-g) were isolated in optically pure form.This is the first chiral synthesis of 2-thiabicyclohept-5-ene ring system.The absolute configuration of the cyclic carbonate (12), which was prepared from the major endo cycloadduct (3c) via the epimerization, or the minor exo compound (6c), was determined as 1R by X-ray analysis.The cycloadduct (3c) was trasformed to a potential intermediate (14) for the synthesis of carbocyclic homonucleosides.