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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence