ChemicalBook CAS DataBase List (1S,4S,5S)-4-Bromo-6-oxabicyclo[3.2.1]octan-7-one

(1S,4S,5S)-4-Bromo-6-oxabicyclo[3.2.1]octan-7-one synthesis

6synthesis methods

Product Name:(1S,4S,5S)-4-Bromo-6-oxabicyclo[3.2.1]octan-7-one
CAS Number:139893-81-5
Molecular formula:C7H9BrO2
Molecular Weight:205.05

(1S)-Cyclohex-3-ene-1-carboxylic acid (II) (5 g) was dissolved in dichloromethane (25 mL). To this solution, N-bromosuccinimide (1.1 mole) was added at room temperature. In two lots, calcium oxide (0.25 mole) was charged to the Suspension. The reaction mixture was stirred at 20 to 25°C for 1 hour and filtered. The bed was washed with dichloromethane (10 mL). The washings were combined with the filtrate, and the solvent was recovered under vacuum at 35 to 40 °C. Deionized water (50 mL) was charged to the solid, heated to 50 °C, stirred for 10 minutes, and filtered. The bed was washed with deionized water (10 mL) and suction dried. The solid was dried under vacuum at 45-50 °C to get (1S,4S,5S)-4-Bromo-6-oxabicyclo[3.2.1]octan-7-one. Yield: 61%

5708-19-0 Synthesis

5708-19-0
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(1S,4S,5S)-4-Bromo-6-oxabicyclo[3.2.1]octan-7-one

139893-81-5
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Yield:139893-81-5 91%

Reaction Conditions:

with N-Bromosuccinimide;sodium hydrogencarbonate in dichloromethane at 5 - 25; for 2.33333 h;

Steps:

1 Example 1: Preparation of (1S,45,55)-4-bromo-6- oxabicyclo[3 .2.1 ]octan-7 -one

Example 1
Preparation of (1S,4S,5S)-4-bromo-6-oxabicyclo[3.2.1]octan-7-one
To a solution of (1 S)-3-cyclohexene-1-carboxylic acid (24.50 g, 194.2 mmol) in dichloromethane (125 mL) was charged sodium bicarbonate (17.13 g, 203.9 mmol), and the reaction mixture was cooled to 5-10° C. N-bromosuccinimide (36.29 g, 203.9 mmol) was added in four portions (over 20 minutes) while maintaining the temperature below 20° C.
The yellow to white suspension was warmed to room temperature and stirring continued for 2 hours until completion of the reaction as measured by TLC (thin-layer chromatography).
The reaction mixture was first treated with 10% aqueous sodium thiosulfate solution (122 mL) yielding a negative test for the presence of bromine using potassium iodide starch test paper, followed by slowly adding a solution of sodium phosphate monobasic (32.20 g, 233.4 mmol) in water (122 mL) due to effervescence.
After separation of the aqueous and organic phases, the organic phase was extracted with saturated ammonium chloride solution (2*122 mL) and the organic phase was dried over sodium sulfate and concentrated in vacuo to dryness to afford (1S,4S,5S)-4-bromo-6-oxabicyclo[3.2.1]octan-7-one as a white solid: 36.24 g (91% yield);

References:

US2018/179226,2018,A1 Location in patent:Paragraph 0247; 0248

67976-82-3 Synthesis