tert-butyl N-(3-oxocycloheptyl)carbamate

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

Procedure: To a solution of tert-butyl 3-oxocycloheptylcarbamate (31.09 g, 137 mmol) in methanol (454 mL) was added sodium borohydride (15.52 g, 410 mmol) portion-wise over ˜10 minutes with mixing. The resulting solution was stirred for 2 h at room temperature and then diluted with water (200 mL). The methanol was removed in-vacuo and the resulting aqueous mixture was diluted further with 500 mL ethyl acetate and 100 mL saturated aqueous sodium bicarbonate. The layers were separated and the aqueous layer back-extracted with 2×1000 mL ethyl acetate. The combined organic layers were dried over anhydrous magnesium sulfate, filtered and concentrated to an oil that was purified by silica gel chromatography (0-50% ethyl acetate in hexanes). Product containing fractions were concentrated to afford tert-butyl 3-hydroxycycloheptylcarbamate (21.1 g, 92 mmol, 67.3% yield). MS (ESI) m/z 230.3 [M+H]+. The above two reactions were repeated starting with 9.52 g cyclohept-2-enone and yielding 9.27 g of tert-butyl 3-hydroxycycloheptylcarbamate. The two batches of tert-butyl 3-hydroxycycloheptylcarbamate were then combined. 29.2 g of the combined material was separated into the 4 constituent stereoisomers (two diastereomers and their corresponding enantiomers) by preparative chiral SFC utilizing multiple injections over a series of 3 separate columns. First column: ChiralPak IC-H, 250×30 mm I.D., isocratic 15% ethanol in CO2, 38° C. Second column: ChiralCel OJ-H, 250×30 mm I.D., isocratic 10% isopropanol in CO2, 38° C. Third column: ChiralPak AD-H, 250×50 mm I.D., isocratic 20% isopropanol in CO2, 38° C. The separated isomers were characterized on an analytical scale Phenomenex Lux Amylose-2 column, 250×4.6 mm I.D., isocratic 15% ethanol in CO, (10 min run time) and labeled as Intermediate 1 to Intermediate 4. with mixing The methanol was removed in-vacuo the resulting aqueous mixture was diluted further with 500 mL ethyl acetate and 100 mL saturated aqueous sodium bicarbonate The layers were separated the aqueous layer back-extracted with 2×1000 mL ethyl acetate The combined organic layers were dried over anhydrous magnesium sulfate filtered concentrated to an oil that was purified by silica gel chromatography (0-50% ethyl acetate in hexanes) Product containing fractions were concentrated

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

Procedure: To a stirring mixture of cyclohept-2-enone (26.96 g, 245.0 mmol) and tert-butyl carbamate (28.7 g, 245 mmol) in DCM (245 mL) was added bismuth nitrate pentahydrate (22.79 g, 47.0 mmol). The resulting mixture was stirred at room temperature overnight. The reaction was diluted reaction with ethyl acetate (500 mL) and water (300 mL) and the biphasic mixture was filtered through a bed of Celite. The bed of Celite was washed well with ethyl acetate and water, and layers of the filtrate separated. The organic layer was concentrated to an oil that was purified by silica gel chromatography (0-40% ethyl acetate in hexanes). Product containing fractions were concentrated to afford the title compound (31.09 g, 137 mmol, 55.9% yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 6.92 (d, J=7.03 Hz, 1H), 3.60 (d, J=8.59 Hz, 1H), 2.55-2.69 (m, 1H), 2.26-2.45 (m, 2H), 1.69-1.93 (m, 3H), 1.44-1.61 (m, 2H), 1.37 (d, J=5.08 Hz, 11H). MS (ESI) m/z 228.5 [M+H]+. The reaction was diluted the biphasic mixture was filtered through a bed of Celite The bed of Celite was washed well with ethyl acetate and water, and layers of the filtrate separated The organic layer was concentrated to an oil that was purified by silica gel chromatography (0-40% ethyl acetate in hexanes) Product containing fractions were concentrated

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

Procedure: To a stirring mixture of cyclohept-2-enone (26.96 g, 245.0 mmol) and tert-butyl carbamate (28.7 g, 245 mmol) in DCM (245 mL) was added bismuth nitrate pentahydrate (22.79 g, 47.0 mmol). The resulting mixture was stirred at room temperature overnight. The reaction was diluted reaction with ethyl acetate (500 mL) and water (300 mL) and the biphasic mixture was filtered through a bed of Celite. The bed of Celite was washed well with ethyl acetate and water, and layers of the filtrate separated. The organic layer was concentrated to an oil that was purified by silica gel chromatography (0-40% ethyl acetate in hexanes). Product containing fractions were concentrated to afford the title compound (31.09 g, 137 mmol, 55.9% yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 6.92 (d, J=7.03 Hz, 1H), 3.60 (d, J=8.59 Hz, 1H), 2.55-2.69 (m, 1H), 2.26-2.45 (m, 2H), 1.69-1.93 (m, 3H), 1.44-1.61 (m, 2H), 1.37 (d, J=5.08 Hz, 11H). MS (ESI) m/z 228.5 [M+H]+. The reaction was diluted the biphasic mixture was filtered through a bed of Celite The bed of Celite was washed well with ethyl acetate and water, and layers of the filtrate separated The organic layer was concentrated to an oil that was purified by silica gel chromatography (0-40% ethyl acetate in hexanes) Product containing fractions were concentrated