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ChemicalBook CAS DataBase List (4R,5R)-(-)-2,2-DIMETHYL-ALPHA,ALPHA,ALPHA',ALPHA'-TETRA(1-NAPHTHYL)-1,3-DIOXOLANE-4,5-DIMETHANOL
137536-94-8

(4R,5R)-(-)-2,2-DIMETHYL-ALPHA,ALPHA,ALPHA',ALPHA'-TETRA(1-NAPHTHYL)-1,3-DIOXOLANE-4,5-DIMETHANOL synthesis

4synthesis methods
-

Yield: 91.8%

Reaction Conditions:

Stage #1:1-Bromonaphthalene with isopropylmagnesium bromide in tetrahydrofuran at 0; for 0.5 h;Inert atmosphere;
Stage #2:diethyl (4R,5R)-2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate in tetrahydrofuran at 65 - 70;

Steps:

5.2 Example 5 Preparation of (4R,5R)-1-Nph-TADDOL
(2) Under nitrogen protection, add 1200 g of tetrahydrofuran, add 520 g of 1-bromonaphthalene, cool the ice bath to approximately 0 °C, and add 850 mL isopropylmagnesium bromide in the form of 3mol/L reagent to control the temperature. T = 6 ° C, stirring 0.5h after the drop: (R, R)-O, O-isopropylidene diethyl tartrate 123g, 1h after the completion of the increase to 65-70 °C temperature reaction 2-4h. The reaction was completed by TLC and 5 L of a saturated aqueous solution of ammonium chloride was slowly added dropwise over 5 hours to terminate the reaction. The mixture was separated by standing, and the aqueous phase was extracted twice with 2 L of ethyl acetate. The organic phases were combined, washed with 3 L of water twice, washed with 2 L of saturated brine, and concentrated to give 357 g of a yellow-brown oil. The target product was obtained by adding 1800 g of a mixed solvent (by volume, ethyl acetate:benzene = 20:1) to obtain the target product: (4R,5R)-2,2-dimethyl-fluorene, anthraquinone, quinoline, quinoa'-tetramine (1-naphthyl)-1,3-dioxane-4,5-dimethanol, namely: (4R,5R)-1-Nph-TADDOL. White crystals, 277 g, yield 91.8%, HPLC: 99.6%, ee value: 99.5%

References:

Tianjin Dikete Technology Co., Ltd.;Zhang Shubing;Xie Yanmin CN107721969, 2018, A Location in patent:Paragraph 0050; 0052

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