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

HRID 852754Notes

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-e1a6ba1c5a194ef0a2aafcd5e2b9d3ed
Source dataset: uspto-grants-2007_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07253196B2

Reaction notes

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