反应详情

To a solution of ethyl 4-methylenecyclohexanecarboxylate (0.15 g, 0.892 mmol) in diglyme (3 mL) was added a solution of sodium 2-chloro-2,2-difluoroacetate (0.544 g, 3.57 mmol) in 5 ml of diglyme via syringe pump at 0.5 ml/h at 150° C. The reaction was cooled to rt, then diluted with DCM and washed with water, brine, dried over Na2SO4, filtered and concentrated. The residue was charged to a 40 g silica gel cartridge which was eluted with a 20 min gradient of 0-20% EtOAc in hexane to yield ethyl 1,1-difluorospiro[2.5]octane-6-carboxylate. 1H NMR (400 MHz, CDCl3) ppm 4.09-4.19 (2H, m), 2.29-2.45 (1H, m), 1.89-2.03 (2H, m), 1.55-1.72 (5H, m), 1.45-1.54 (1H, m), 1.31-1.39 (1H, m), 1.21-1.30 (3H, m), 0.84-0.94 (1H, m).

1. washwashed with water, brine
2. dry with materialdried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated
5. additionThe residue was charged to a 40 g silica gel cartridge which
6. washwas eluted with a 20 min gradient of 0-20% EtOAc in hexane