- 2 - ((4R, 6R) - 6-aminomethyl-ethyl -2,2-dimethyl -1,3-dioxane-4-yl) acetate simple method for preparing
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The invention relates to a simple preparation method of 2-((4R,6R)-6-aminoethyl-2,2-dimethyl-1,3-dioxyhexacyclo-4-yl)acetate (I). The method comprises the following steps: reacting 3-cyanopropylene (II) and 3,3-dialkoxypropionate (III) or 3-alkoxyacrylate (IV) under the catalytic action of Lewis acid to prepare 2-((4R,6R)-6-cyanomethyl-2-ester-methyl-1,3-dioxyhexacyclo-4-yl)acetate (V), removing the solvent, directly carrying out blocking group conversion to prepare 2-((4R,6R)-6-cyanomethyl-2,2-dimethyl-1,3-dioxyhexacyclo-4-yl)acetate (VI), and carrying out Raney nickel catalytic hydrogenation two-step reaction to prepare (I). The stable form of the hexatomic ring chair-structure equatorial bond is utilized to construct the chiral center without using any additional chiral assistant. The method has the advantages of accessible raw materials, short reaction procedure and low cost, avoids carbonyl asymmetric reduction, is simple and environment-friendly, and is industrial production.
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Paragraph 0054-0055; 0062-0063
(2017/02/28)
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- Method for preparing 3,5-di-substituted hydroxyl-6-substituted capronate derivative
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The invention discloses a method for preparing a 3,5-di-substituted hydroxyl-6-substituted capronate derivative shown as a general formula I. The method comprises a step that carboxylate shown in a general formula II and RM are subjected to a reaction under effect of a cuprous salt catalyst. The method has the advantages that the process is simple, cost is low, a catalyst with expensive price can be avoided, generation of a by-product is reduced, the post-treatment is simple, operation is easy, reaction yield is greatly increased, and the method is more suitable for large-scale industrial production.
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Paragraph 0024; 0025; 0026; 0027; 0028; 0029
(2016/10/10)
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- Asymmetric synthesis of the HMG-CoA reductase inhibitor atorvastatin calcium: An organocatalytic anhydride desymmetrization and cyanide-free side chain elongation approach
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An efficient asymmetric synthesis of atorvastatin calcium has been achieved from commercially available diethyl 3-hydroxyglutarate through a novel approach that involves an organocatalytic enantioselective cyclic anhydride desymmetrization to establish C(
- Chen, Xiaofei,Xiong, Fangjun,Chen, Wenxue,He, Qiuqin,Chen, Fener
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p. 2723 - 2728
(2014/04/17)
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- PROCESS FOT THE PREPARATION OF (4-HYDROXY-6-OXO-TETRAHYDROPYRAN-2-YL) ACETONITRILE AND DERIVATIVES THEREOF
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The invention relates to a process for the preparation of (4-hydroxy-6-oxo-tetrahydro-pyran-2-yl)-acetonitrile from 6-X-substituted-methyl-4-hydroxy-tetrahydro-pyran-2-one, wherein X stands for a leaving group, by reacting 6-X-substituted-methyl-4-hydroxy-tetrahydro-pyran-2-one with a cyanide ion in water and by subsequent lowering of the pH to a pH between 0 and 5. (4-hydroxy-6-oxo-tetrahydro-pyran-2-yl)-acetonitrile and other compounds obtainable from (4-hydroxy-6-oxo-tetrahydro-pyran-2-yl)-acetonitrile may suitably be used in the preparation of a pharmaceutical preparation, more in particular in the preparation of statins, more in particular in the preparation of Atorvastatine or a salt thereof, for instance its calcium salt. The invention also relates to (4-hydroxy-6-oxo-tetrahydro-pyran-2-yl)-acetonitrile and other compounds obtainable therefrom.
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