Water → 4-(1,3-Dithian-2-ylidene)-6-fluoro-3,4-dihydro-2H-chromene

HRID 1158064Notes

Reaction equation

C[Si](C)(C)[CH:3]1[S:8][CH2:7][CH2:6][CH2:5][S:4]1.[Li]CCCC.[F:16][C:17]1[CH:18]=[C:19]2[C:24](=[CH:25][CH:26]=1)[O:23][CH2:22][CH2:21][C:20]2=O.O>C1COCC1>[S:4]1[CH2:5][CH2:6][CH2:7][S:8][C:3]1=[C:20]1[C:19]2[C:24](=[CH:25][CH:26]=[C:17]([F:16])[CH:18]=2)[O:23][CH2:22][CH2:21]1

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 2-trimethylsilyl-1,3-dithiane (5.10 g, 26.5 mmol) in 50 mL of anhydrous THF at −60° C. under N2 was added drop-wise n-BuLi (1.6 M solution in hexanes, 16.6 mL, 26.5 mmol). The mixture was left to warm slowly to 0° C. over 3 h and subsequently cooled to −60° C. A solution of 6-fluoro-2,3-dihydrochromen-4-one (4.40 g, 26.5 mmol) in 25 mL of THF was added drop-wise. The mixture was slowly warmed to ambient temperature overnight, then poured into water, and extracted with EtOAc. The combined organic portions were washed with brine, and conc. in vacuo. The crude product was purified by flash column chromatography (0 to 10% of EtOAc in hexanes). The title compound was obtained as a pale oil.

Workup

waitThe mixture was left
temperaturesubsequently cooled to −60° C
temperatureThe mixture was slowly warmed to ambient temperature overnight
extractionextracted with EtOAc
washThe combined organic portions were washed with brine
customThe crude product was purified by flash column chromatography (0 to 10% of EtOAc in hexanes)

Sources & evidence

ORD record: ord-8e751b2b4ab74edeb7669636b0ff1028
Source dataset: uspto-grants-2010_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07807700B2

Reaction notes

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