tert-Butyl (4R-cis)-6-formaldehydel-2,2-dimethyl-1,3-dioxane-4-acetate synthesis
- Product Name:tert-Butyl (4R-cis)-6-formaldehydel-2,2-dimethyl-1,3-dioxane-4-acetate
- CAS Number:124752-23-4
- Molecular formula:C13H22O5
- Molecular Weight:258.31
124655-09-0
124752-23-4
General procedure for the synthesis of tert-butyl (4R,6S)-6-formyl-2,2-dimethyl-1,3-dioxane-4-acetate from (4R,6S)-6-hydroxymethyl-2,2-dimethyl-1,3-dioxane-4-acetate: tert-butyl (4R,6S)-6-hydroxymethyl-2,2-dimethyl-1,3-dioxane-4-acetate ( 10.0 g, 0.0385 mol) was dissolved in a solvent mixture of dimethyl sulfoxide (15.0 g, 0.192 mol) and dichloromethane (100 mL) and the reaction system was subsequently cooled to 0 to -5 °C. After being maintained at this temperature for 15 minutes, diisopropylethylamine (17.42 g, 0.1347 mol) was slowly added and stirring was continued at 0 to -5 °C for 15 minutes. Another flask was taken and a suspension was prepared by sequentially adding pyridine-sulfur trioxide complex (12.25 g, 0.077 mol), pyridine (6.09 g, 0.077 mol) and dimethyl sulfoxide (15.0 g, 0.192 mol) at room temperature and stirring for 10 minutes. This suspension was slowly added to the aforementioned cooled dichloromethane solution, keeping the reaction temperature at 0 to -5°C and continuing to stir for 1 hour. Upon completion of the reaction, the reaction was quenched by the addition of water (50.0 mL) and stirred for 10 minutes. Liquid-liquid separation was then performed and the aqueous phase was back-extracted with dichloromethane (2 x 20 mL). The organic phases were combined, washed sequentially with water (3 x 100.0 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent to give the crude product. The crude product was dried under reduced pressure at 40 to 45 °C for 1 h. The final product was tert-butyl (4R,6S)-6-formyl-2,2-dimethyl-1,3-dioxohexane-4-acetate (9.22 g, 93.0% yield).
![tert-Butyl (4R-cis)-6-[(acetyloxy)methyl]-2,2-dimethyl-1,3-dioxane-4-acetate](/CAS/GIF/154026-95-6.gif)
154026-95-6
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124752-23-4
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Yield:124752-23-4 96.1%
Reaction Conditions:
Stage #1:(4R-cis)-6-[(acetyloxy)methyl]-2,2-dimethyl-1,3-dioxane-4-acetic acid tert-butyl ester with methanol;potassium carbonate for 3 h;
Stage #2: with sodium hypochlorite;2,2,6,6-Tetramethyl-1-piperidinyloxy free radical;sodium hydrogencarbonate;potassium bromide in dichloromethane at -5 - 5; for 1 h;
Steps:
11 Example 11
In a 500 mL three-necked flask, 10 g of D-5, 100 mL of methanol and 4.0 g of potassium carbonate were successively added, and the mixture was stirred for 3 hours, filtered, and the filtrate was concentrated to dryness under reduced pressure at 35 to 45 °C.The resulting syrup was dissolved in 150 mL of dichloromethane, and 3.0 g of sodium hydrogencarbonate, 0.5 g of potassium bromide and 0.4 g of TEMPO were sequentially added.After the mixture was stirred and cooled to -5 to 5 ° C, 50.0 g of an 8% sodium hypochlorite solution was added dropwise.After the completion of the dropwise addition, the mixture was stirred at -5 to 5 ° C for 1 hour.The reaction was monitored by TLC, and the reaction was quenched by the addition of 0.7 g of sodium thiosulfate and 10.0 g of water.The layers were static and the aqueous layer was stripped with 100 mL of dichloromethane.The organic layers were combined and the organic layer was washed with 2×200 mL water.The washed organic layer was dried under reduced pressure at 35 to 45 ° C to give a pale red solid 8.2 g of D-7, yield 96.1%.
References:
Zhejiang Hongyuan Pharmaceutical Co., Ltd.;Mei Guangyao;Wang Haibo;Jin Hui;Kuang Hongfu;Wang Yabin;Miao Hanhui;Xu Chenli CN109574830, 2019, A Location in patent:Paragraph 0083-0085
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124752-23-4
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