tert-butyl-cyclopent-3-en-1-yloxy-dimethylsilane

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

Procedure: To a flask was added tert-butyl(cyclopent-3-en-1-yloxy)dimethylsilane (0.5 g, 2.52 mmol) and rhodium(II) acetate dimer (22 mg, 0.05 mmol). The flask was evacuated and purged 5 times with argon. Dichloromethane (8.4 mL) was added and the flask was evacuated and purged 5 times with argon. In a separate flask, ethyl diazoacetate (0.37 mL, 3.02 mmol) was added. The flask was evacuated and purged with argon five times. Dichloromethane (8.4 mL) was added and the solution was added to the first flask via syringe pump over a six hour time period and then allowed to stir overnight. The mixture was filtered over a pad of celite and then concentrated. Flash chromatography was used for purification to yield ethyl 3-{[tert-butyl(dimethyl)silyl]oxy}bicyclo[3.1.0]hexane-6-carboxylate (524 mg, 1.84 mmol, 73% yield). 1H NMR (500 MHz, CDCl3) δ 4.13-4.03 (m, 2H), 2.37-2.20 (m, 1H), 2.20-2.12 (m, 1H), 2.11-1.96 (m, 1H), 1.94-1.70 (m, 4H), 1.35-1.14 (m, 4H), 0.89-0.79 (m, 9H), 0.05-−0.11 (m, 6H). The flask was evacuated purged 5 times with argon Dichloromethane (8.4 mL) was added the flask was evacuated purged 5 times with argon The flask was evacuated purged with argon five times Dichloromethane (8.4 mL) was added the solution was added to the first flask via syringe pump over a six hour time period The mixture was filtered over a pad of celite concentrated Flash chromatography was used for purification

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

Procedure: To a flask was added tert-butyl(cyclopent-3-en-1-yloxy)dimethylsilane (0.5 g, 2.52 mmol) and rhodium(II) acetate dimer (22 mg, 0.05 mmol). The flask was evacuated and purged 5 times with argon. Dichloromethane (8.4 mL) was added and the flask was evacuated and purged 5 times with argon. In a separate flask, ethyl diazoacetate (0.37 mL, 3.02 mmol) was added. The flask was evacuated and purged with argon five times. Dichloromethane (8.4 mL) was added and the solution was added to the first flask via syringe pump over a six hour time period and then allowed to stir overnight. The mixture was filtered over a pad of celite and then concentrated. Flash chromatography was used for purification to yield ethyl 3-{[tert-butyl(dimethyl)silyl]oxy}bicyclo[3.1.0]hexane-6-carboxylate (524 mg, 1.84 mmol, 73% yield). 1H NMR (500 MHz, CDCl3) δ 4.13-4.03 (m, 2H), 2.37-2.20 (m, 1H), 2.20-2.12 (m, 1H), 2.11-1.96 (m, 1H), 1.94-1.70 (m, 4H), 1.35-1.14 (m, 4H), 0.89-0.79 (m, 9H), 0.05-−0.11 (m, 6H). The flask was evacuated purged 5 times with argon Dichloromethane (8.4 mL) was added the flask was evacuated purged 5 times with argon The flask was evacuated purged with argon five times Dichloromethane (8.4 mL) was added the solution was added to the first flask via syringe pump over a six hour time period The mixture was filtered over a pad of celite concentrated Flash chromatography was used for purification

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

Procedure: Cyclopent-3-en-1-ol (10 g, 118.9 mmol) was dissolved in DMF (100 mL) at 0° C., then 1H-imidazole (17.29 mL, 261.5 mmol) was added, followed by tert-butyl(chloro)-dimethylsilane (21.5 g, 142.7 mmol). The mixture was warmed to room temperature and stirred for 14 h. The mixture was diluted with ethyl acetate (300 mL), washed with 5% aqueous LiCl solution (2×100 mL) and brine (50 mL), then dried over sodium sulfate, filtered, and concentrated. The crude residue was purified by chromatography, eluting with 0-10% EtOAc in hexane, to afford the title compound (17.2 g, 73%) as a colourless clear liquid. δH (250 MHz, CDCl3) 5.66 (s, 2H), 4.53 (tt, J 7.0, 3.6 Hz, 1H), 2.57 (dd, J 15.2, 6.8 Hz, 2H), 2.27 (dd, J 15.3, 3.6 Hz, 2H), 0.89 (s, 9H), 0.06 (s, 6H). washed with 5% aqueous LiCl solution (2×100 mL) and brine (50 mL) dried over sodium sulfate filtered concentrated The crude residue was purified by chromatography eluting with 0-10% EtOAc in hexane

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

Procedure: To a flask was added tert-butyl(cyclopent-3-en-1-yloxy)dimethylsilane (0.5 g, 2.52 mmol) and rhodium(II) acetate dimer (22 mg, 0.05 mmol). The flask was evacuated and purged 5 times with argon. Dichloromethane (8.4 mL) was added and the flask was evacuated and purged 5 times with argon. In a separate flask, ethyl diazoacetate (0.37 mL, 3.02 mmol) was added. The flask was evacuated and purged with argon five times. Dichloromethane (8.4 mL) was added and the solution was added to the first flask via syringe pump over a six hour time period and then allowed to stir overnight. The mixture was filtered over a pad of celite and then concentrated. Flash chromatography was used for purification to yield ethyl 3-{[tert-butyl(dimethyl)silyl]oxy}bicyclo[3.1.0]hexane-6-carboxylate (524 mg, 1.84 mmol, 73% yield). 1H NMR (500 MHz, CDCl3) δ 4.13-4.03 (m, 2H), 2.37-2.20 (m, 1H), 2.20-2.12 (m, 1H), 2.11-1.96 (m, 1H), 1.94-1.70 (m, 4H), 1.35-1.14 (m, 4H), 0.89-0.79 (m, 9H), 0.05-−0.11 (m, 6H). The flask was evacuated purged 5 times with argon Dichloromethane (8.4 mL) was added the flask was evacuated purged 5 times with argon The flask was evacuated purged with argon five times Dichloromethane (8.4 mL) was added the solution was added to the first flask via syringe pump over a six hour time period The mixture was filtered over a pad of celite concentrated Flash chromatography was used for purification

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

Procedure: To a flask was added tert-butyl(cyclopent-3-en-1-yloxy)dimethylsilane (0.5 g, 2.52 mmol) and rhodium(II) acetate dimer (22 mg, 0.05 mmol). The flask was evacuated and purged 5 times with argon. Dichloromethane (8.4 mL) was added and the flask was evacuated and purged 5 times with argon. In a separate flask, ethyl diazoacetate (0.37 mL, 3.02 mmol) was added. The flask was evacuated and purged with argon five times. Dichloromethane (8.4 mL) was added and the solution was added to the first flask via syringe pump over a six hour time period and then allowed to stir overnight. The mixture was filtered over a pad of celite and then concentrated. Flash chromatography was used for purification to yield ethyl 3-{[tert-butyl(dimethyl)silyl]oxy}bicyclo[3.1.0]hexane-6-carboxylate (524 mg, 1.84 mmol, 73% yield). 1H NMR (500 MHz, CDCl3) δ 4.13-4.03 (m, 2H), 2.37-2.20 (m, 1H), 2.20-2.12 (m, 1H), 2.11-1.96 (m, 1H), 1.94-1.70 (m, 4H), 1.35-1.14 (m, 4H), 0.89-0.79 (m, 9H), 0.05-−0.11 (m, 6H). The flask was evacuated purged 5 times with argon Dichloromethane (8.4 mL) was added the flask was evacuated purged 5 times with argon The flask was evacuated purged with argon five times Dichloromethane (8.4 mL) was added the solution was added to the first flask via syringe pump over a six hour time period The mixture was filtered over a pad of celite concentrated Flash chromatography was used for purification

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

Procedure: To a flask was added tert-butyl(cyclopent-3-en-1-yloxy)dimethylsilane (0.5 g, 2.52 mmol) and rhodium(II) acetate dimer (22 mg, 0.05 mmol). The flask was evacuated and purged 5 times with argon. Dichloromethane (8.4 mL) was added and the flask was evacuated and purged 5 times with argon. In a separate flask, ethyl diazoacetate (0.37 mL, 3.02 mmol) was added. The flask was evacuated and purged with argon five times. Dichloromethane (8.4 mL) was added and the solution was added to the first flask via syringe pump over a six hour time period and then allowed to stir overnight. The mixture was filtered over a pad of celite and then concentrated. Flash chromatography was used for purification to yield ethyl 3-{[tert-butyl(dimethyl)silyl]oxy}bicyclo[3.1.0]hexane-6-carboxylate (524 mg, 1.84 mmol, 73% yield). 1H NMR (500 MHz, CDCl3) δ 4.13-4.03 (m, 2H), 2.37-2.20 (m, 1H), 2.20-2.12 (m, 1H), 2.11-1.96 (m, 1H), 1.94-1.70 (m, 4H), 1.35-1.14 (m, 4H), 0.89-0.79 (m, 9H), 0.05-−0.11 (m, 6H). The flask was evacuated purged 5 times with argon Dichloromethane (8.4 mL) was added the flask was evacuated purged 5 times with argon The flask was evacuated purged with argon five times Dichloromethane (8.4 mL) was added the solution was added to the first flask via syringe pump over a six hour time period The mixture was filtered over a pad of celite concentrated Flash chromatography was used for purification

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

Procedure: Cyclopent-3-en-1-ol (10 g, 118.9 mmol) was dissolved in DMF (100 mL) at 0° C., then 1H-imidazole (17.29 mL, 261.5 mmol) was added, followed by tert-butyl(chloro)-dimethylsilane (21.5 g, 142.7 mmol). The mixture was warmed to room temperature and stirred for 14 h. The mixture was diluted with ethyl acetate (300 mL), washed with 5% aqueous LiCl solution (2×100 mL) and brine (50 mL), then dried over sodium sulfate, filtered, and concentrated. The crude residue was purified by chromatography, eluting with 0-10% EtOAc in hexane, to afford the title compound (17.2 g, 73%) as a colourless clear liquid. δH (250 MHz, CDCl3) 5.66 (s, 2H), 4.53 (tt, J 7.0, 3.6 Hz, 1H), 2.57 (dd, J 15.2, 6.8 Hz, 2H), 2.27 (dd, J 15.3, 3.6 Hz, 2H), 0.89 (s, 9H), 0.06 (s, 6H). washed with 5% aqueous LiCl solution (2×100 mL) and brine (50 mL) dried over sodium sulfate filtered concentrated The crude residue was purified by chromatography eluting with 0-10% EtOAc in hexane

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

Procedure: To a flask was added tert-butyl(cyclopent-3-en-1-yloxy)dimethylsilane (0.5 g, 2.52 mmol) and rhodium(II) acetate dimer (22 mg, 0.05 mmol). The flask was evacuated and purged 5 times with argon. Dichloromethane (8.4 mL) was added and the flask was evacuated and purged 5 times with argon. In a separate flask, ethyl diazoacetate (0.37 mL, 3.02 mmol) was added. The flask was evacuated and purged with argon five times. Dichloromethane (8.4 mL) was added and the solution was added to the first flask via syringe pump over a six hour time period and then allowed to stir overnight. The mixture was filtered over a pad of celite and then concentrated. Flash chromatography was used for purification to yield ethyl 3-{[tert-butyl(dimethyl)silyl]oxy}bicyclo[3.1.0]hexane-6-carboxylate (524 mg, 1.84 mmol, 73% yield). 1H NMR (500 MHz, CDCl3) δ 4.13-4.03 (m, 2H), 2.37-2.20 (m, 1H), 2.20-2.12 (m, 1H), 2.11-1.96 (m, 1H), 1.94-1.70 (m, 4H), 1.35-1.14 (m, 4H), 0.89-0.79 (m, 9H), 0.05-−0.11 (m, 6H). The flask was evacuated purged 5 times with argon Dichloromethane (8.4 mL) was added the flask was evacuated purged 5 times with argon The flask was evacuated purged with argon five times Dichloromethane (8.4 mL) was added the solution was added to the first flask via syringe pump over a six hour time period The mixture was filtered over a pad of celite concentrated Flash chromatography was used for purification