تفاعل #44471

معادلة التفاعل

Benzyl(R)-2-((S)-2,5-dihydrofuran-2-yl)-2-hydroxyethylcarbamate

ammonium chloride

bromotosylate

(3S,3aS,6S,6aS)-6-Bromohexahydrofuro[3,2-b]furan-3-yl 4-methylbenzenesulfonate

ammonia

→

(R)-2-amino-1-((S)-2,5-dihydrofuran-2-yl)ethanol

المذيبات

water

propan-2-ol

methanol

propan-2-ol

ظروف التفاعل

المعالجة

1. 1
   ترشيحbefore filtering the suspension through celite in vacuo
2. 2
   غسيلThe filter cake was washed with diethyl ether (60 mL)
3. 3
   workup.ADDITIONHydrochloric acid (1M, 60 mL) was added to the filtrate
4. 4
   أخرىthe organic phase separated
5. 5
   استخلاصThe aqueous layer was extracted with diethyl ether (60 mL)
6. 6
   غسيلthe combined organic phase was washed with brine (60 mL)
7. 7
   تجفيفdried (MgSO4)
8. 8
   ترشيحfiltered
9. 9
   workup.DISSOLUTIONThe residue was dissolved in ammonium hydroxide (18 mL)
10. 10
    أخرىthe solvents were removed in vacuo
11. 11
    أخرىThe residue was azeotroped with diethyl ether (3×10 mL)

الإجراء التجريبي

Alternative preparation of Benzyl(R)-2-((S)-2,5-dihydrofuran-2-yl)-2-hydroxyethylcarbamate (18); Zinc and ‘One-pot’ procedure. A solution of ammonium chloride (600 mg, 11.2 mmol) in water (7.5 mL) was added to a solution of bromotosylate (47) (3.0 g, 8.26 mmol) in propan-2-ol (15 mL) under argon. Zinc dust (600 mg, 9.2 mmol) was then added in portions over 4 minutes and the mixture was stirred for 16 hours before filtering the suspension through celite in vacuo. The filter cake was washed with diethyl ether (60 mL). Hydrochloric acid (1M, 60 mL) was added to the filtrate then the organic phase separated. The aqueous layer was extracted with diethyl ether (60 mL) then the combined organic phase was washed with brine (60 mL), then dried (MgSO4), filtered and reduced in vacuo. The residue was dissolved in ammonium hydroxide (18 mL) and a solution of ammonia in propan-2-ol (12 mL, 2.0M, 24 mmol), then divided into two equal portions and heated in sealed tubes at 75° C. for 16 hours. The mixtures were combined using methanol then the solvents were removed in vacuo. The residue was azeotroped with diethyl ether (3×10 mL) to obtain (R)-2-amino-1-((S)-2,5-dihydrofuran-2-yl)ethanol which was used without further purification.

المصدر