تفاعل #682045

معادلة التفاعل

6-bromo-3,3-bis(hydroxymethyl)-2,2-dimethyl-2,3-dihydro-4H-chromen-4-one

triphenylphosphine

diisopropyl azodicarboxylate

→

6-bromo-2,2-dimethyl-4H-spiro[chromene-3,3′-oxetan]-4-one

المردود 34.9%

المذيبات

THF

toluene

ظروف التفاعل

المعالجة

1. 1
   ترشيحthe mixture was filtered off
2. 2
   غسيلThe filtrate was washed with 1 M aqueous NaOH (three times), water and brine
3. 3
   تجفيفdried over MgSO4
4. 4
   ترشيحfiltered
5. 5
   أخرىThe filtrate was evaporated
6. 6
   أخرىto give a crude product
7. 7
   أخرىThe crude product was purified with column chromatography on silica gel (Hexane-EtOAc

الإجراء التجريبي

To a mixture of 6-bromo-3,3-bis(hydroxymethyl)-2,2-dimethyl-2,3-dihydro-4H-chromen-4-one (6.76 g, 21.4 mmol), zinc bis(dimethyldithiocarbamate) (26.2 g, 85.8 mmol) and triphenylphosphine (8.44 g, 32.2 mmol) in THF (0.20 L) was added diisopropyl azodicarboxylate (1.9 M solution in toluene, 16.9 mL, 32.2 mmol) in an ice-water bath. The mixture was stirred overnight at ambient temperature. The mixture was diluted with toluene (0.20 L), and the mixture was filtered off. The filtrate was washed with 1 M aqueous NaOH (three times), water and brine, dried over MgSO4 and filtered. The filtrate was evaporated to give a crude product. The crude product was purified with column chromatography on silica gel (Hexane-EtOAc, a linear gradient of EtOAc from 0 to 20%) to afford 6-bromo-2,2-dimethyl-4H-spiro[chromene-3,3′-oxetan]-4-one (2.22 g).

المصدر