ethyl spiro[2.5]octane-6-carboxylate

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: At 0° C., to a solution of ethyl 4-methylenecyclohexanecarboxylate (0.08 g) in DCE (1 mL) was added chloroiodomethane (0.110 mL, 1.522 mmol), followed by the addition of 1 N diethylzinc in hexane (0.761 mL, 0.761 mmol). The reaction was stirred at 0° C. for 1 hr, then stirred at rt for 18 hrs. The reaction mixture was diluted with EtOAc and 1 N HCl, the organic phase was washed with sat. NaCl, dried over anhydrous Na2SO4, filtered and concentrated. The crude product was charged to a 25 g silica gel cartridge which was eluted with a 20 min gradient of 0-6% EtOAc in hexane to yield ethyl spiro[2.5]octane-6-carboxylate. 1H NMR (400 MHz, CDCl3) δ ppm 4.08-4.18 (2H, m), 2.32 (1H, tq, J=11.01, 3.53 Hz), 1.85-1.93 (2H, m), 1.53-1.74 (4H, m), 1.28-1.35 (2H, m), 1.22-1.28 (3H, m), 0.28 (2H, ddd, J=8.53, 5.52, 1.51 Hz), 0.17-0.25 (2H, m). stirred at rt for 18 hrs the organic phase was washed with sat. NaCl dried over anhydrous Na2SO4 filtered concentrated The crude product was charged to a 25 g silica gel cartridge which was eluted with a 20 min gradient of 0-6% EtOAc in hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This intermediate was prepared from (((2-methylenecyclohexyl)methoxy)methyl)benzene by using the same protocol as described for ethyl spiro[2.5]octane-6-carboxylate (I-7A). 1H NMR (400 MHz, CDCl3) δ 7.35-7.31 (m, 4H), 7.29 (m, 1H) 4.49 (q, J=12.4 Hz, 2H), 3.52 (t, J=9.2 Hz, 1H), 3.41 (dd, J=9.2, 5.2 Hz, 1H), 1.72-1.67 (m, 1H), 1.49-1.43 (m, 4H), 1.33-1.26 (m, 1H), 0.88-0.85 (m, 1H), 0.37-0.31 (m, 2H), 0.19-0.14 (m, 2H). MS m/z 231.1 (M+1).

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: At 0° C., to a solution of ethyl 4-methylenecyclohexanecarboxylate (0.08 g) in DCE (1 mL) was added chloroiodomethane (0.110 mL, 1.522 mmol), followed by the addition of 1 N diethylzinc in hexane (0.761 mL, 0.761 mmol). The reaction was stirred at 0° C. for 1 hr, then stirred at rt for 18 hrs. The reaction mixture was diluted with EtOAc and 1 N HCl, the organic phase was washed with sat. NaCl, dried over anhydrous Na2SO4, filtered and concentrated. The crude product was charged to a 25 g silica gel cartridge which was eluted with a 20 min gradient of 0-6% EtOAc in hexane to yield ethyl spiro[2.5]octane-6-carboxylate. 1H NMR (400 MHz, CDCl3) δ ppm 4.08-4.18 (2H, m), 2.32 (1H, tq, J=11.01, 3.53 Hz), 1.85-1.93 (2H, m), 1.53-1.74 (4H, m), 1.28-1.35 (2H, m), 1.22-1.28 (3H, m), 0.28 (2H, ddd, J=8.53, 5.52, 1.51 Hz), 0.17-0.25 (2H, m). stirred at rt for 18 hrs the organic phase was washed with sat. NaCl dried over anhydrous Na2SO4 filtered concentrated The crude product was charged to a 25 g silica gel cartridge which was eluted with a 20 min gradient of 0-6% EtOAc in hexane