* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With 2,6-dimethylpyridine; In dichloromethane; at 0℃; for 2 - 2.16667h;Product distribution / selectivity;
Example 1 : Compound 2[00161] 6-Hydroxy-2-tetralone (4.0 g, 24.7 mmol) is dissolved in methylene chloride (50 mL) and cooled to 0 C under inert atmosphere. Trifluoromethyl sulfonyl anhydride (5.55 g, 25.0 mmol) is added to the reaction. 2,6-Lutidine (3.2 g, 30 mmol) is introduced dropwise over 10 minutes and the reaction is stirred at 0 C for an additional 2 hours. The reaction volume is reduced to about 10 mL in vacuo and filtered to remove insoluble material. The filter cake is washed with ether (2 X 25 mL), the organic layers combined and solvent removed in vacuo leaving a thick residue that is utilized in the next step without further purification
With sodium tetrahydroborate; ethanol; at 20℃;Cooling with ice;
General procedure: 1.3 mmol NaBH4 was added to 1.0 mmol of 1a in dry ethanol (10 mL) stirred in an ice bath. Afterwards, the suspension was stirred overnight at room temperature. The reaction was quenched by addition of 1.0 N HCl until the pH reaches 7.0, and the ethanol was evaporated under reduced pressure. The product was extracted with diethyl ether (25 mL x 2), washed with sodium bicarbonate (15 mL), and water (10 mL). The resulting solution was dried over MgSO4, filtered, and evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate, 4:1) to give the corresponding rac-1b. 2a-7a (1.02 mmol~ 5.2 mmol) were reduced similarly. The 1H-NMR spectra of alcohols 1b,1 2b,2 3b,2 4b,3 and 5-7b2 were in agreement with that reported in the literature.
6-((2-chloro-6-ethylbenzyl)oxy)-3,4-dihydronaphthalen-2(1H)-one[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
240 mg
With diisopropyl (E)-azodicarboxylate; triphenylphosphine; In tetrahydrofuran; at 0 - 20℃;
73.1 6-((2-chloro-6-ethylbenzyl)oxy)-3,4-dihydronaphthalen-2(1H)-one (E)-Diisopropyl diazene-1,2-dicarboxylate (DIAD, 1.499 ml, 7.71 mmol)) was added to a solution of 6-hydroxytetralone (1 g, 6.17 mmol), (2-chloro-6-ethylphenyl)methanol (1.206 g, 6.78 mmol) and triphenylphosphine (2.021 g, 7.71 mmol) in THF (20 ml) at 0 C. and stirred at RT overnight. The volatile components were removed and the crude product purified by chromatography (silica gel) affording 6-((2-chloro-6-ethylbenzyl)oxy)-3,4-dihydronaphthalen-2(1H)-one (240 mg) as a pale yellow oil.
ethyl 3-((6-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)amino)propanoate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
6.1. Ethyl 3-((6-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)amino)propanoate A mixture of <strong>[52727-28-3]6-hydroxy-3,4-dihydronaphthalen-2(1H)-one</strong> (1.5 g, 9.25 mmol), Titanium tetraisopropylate (5.50 ml, 18.50 mmol) and ethyl 3-aminopropanoate hydrochloride (1.705 g, 11.10 mmol) in dry THF (10 ml) was stirred for 8 h at RT under Argon. Sodium borohydride (1.050 g, 27.7 mmol) and ethanol (10 ml) were added and the resulting mixture was stirred for 12 h at RT. The mixture was diluted with 15 ml NaHCO3 and 150 ml DCM filtered over celite and extracted with 50 ml DCM. The combined organic layers were washed with water and brine to obtain crude ethyl 3-((6-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)amino)propanoate (1.26 g).
With acetophenone reductase from Geotrichum candidum NBRC 4597; NAD; isopropyl alcohol; In aq. buffer; at 30℃; for 14h;pH 7.2;Enzymatic reaction;
General procedure: Reactions were performed in 50 mL 100 mM HEPES-NaOH buffer (pH 7.2) consisting of 1.4mM NAD+, 0.29 mmol~0.84 mmol of 1a-7a, cofactor regeneration reagent written in TableS4, and purified GcAPRD with the amount written in Table S4. All reactions were done for 14h at 30 C with a rotational speed of 130 rpm. Organic phase was extracted with diethyl ether,dried over MgSO4, and evaporated under reduced pressure. Corresponding alcohols werepurified by silica gel column chromatography (hexane:ethyl acetate, 4:1) and characterized by1H-NMR analysis. ee were determined by chiral GC (1a-3a, 5a, 6a) or LC (4a, 7a) analysis,and the absolute configurations were determined by comparing the optical rotation values ofthe products with the literature.2,3,8-11 The 1H-NMR spectra of alcohols 1b,1 2b,2 3b,2 4b,3 and5-7b2 were in agreement with that reported in the literature
With glucose dehydrogenase; D-glucose; acetophenone reductase from Geotrichum candidum NBRC 4597, mutant Trp288Ser; NAD; isopropyl alcohol; In aq. buffer; at 30℃; for 3h;pH 7.2;Enzymatic reaction;
General procedure: Reductions were performed in 3.0 mL of 100 mM HEPES-NaOH buffer (pH 7.2) consistingof 0.50 mM NAD+, 11 mM of substrate, 1.5% v/v of 2-propanol, 167 mM of glucose, glucose dehydrogenase with the amount needed to achieve 2.5 mumol/min oxidation of glucose to gluconic acid, and purified GcAPRD with the amount needed to achieve 0.50 mumol/min reduction of each substrate to its corresponding alcohol. Reductions were done for 3 h at 30 C with a shaking speed of 200 rpm. A part of the reaction mixture was extracted with diethylether for yield determination by using chiral GC. The remaining reaction mixture was extractedwith dichloromethane, dried over MgSO4, and used for propionylation reaction by propionylchloride to determine the ee by chiral GC analysis. Meanwhile, for 4a, the reaction mixture was extracted with ethyl acetate for yield and ee determination by chiral HPLC analysis. Absolute configurations were determined by comparing retention times of 4b or propionatesof 2b, 3b, 5b, and 7b with samples prepared by wild type preparative scale reduction.