Ethyl diazoacetate → Ethyl 3-{[tert-butyl(dimethyl)silyl]oxy}bicyclo[3.1.0]hexane-6-carboxylate
Reaktionsgleichung
[C:1]([Si:5]([O:8][CH:9]1[CH2:13][CH:12]=[CH:11][CH2:10]1)([CH3:7])[CH3:6])([CH3:4])([CH3:3])[CH3:2].[N+](=[CH:16][C:17]([O:19][CH2:20][CH3:21])=[O:18])=[N-]>CC([O-])=O.CC([O-])=O.CC([O-])=O.CC([O-])=O.[Rh+2].[Rh+2]>[Si:5]([O:8][CH:9]1[CH2:13][CH:12]2[CH:11]([CH:16]2[C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:10]1)([C:1]([CH3:4])([CH3:2])[CH3:3])([CH3:7])[CH3:6]Komponenten
4
Versuchsvorschrift
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).