[C:1]1([C:8](OC)=[O:9])([C:4]([O:6][CH3:7])=[O:5])[CH2:3][CH2:2]1.CC(C[AlH]CC(C)C)C.[Cl-].[NH4+].Cl>ClCCl>[CH:8]([C:1]1([C:4]([O:6][CH3:7])=[O:5])[CH2:3][CH2:2]1)=[O:9]
Dimethyl cyclopropane-1,1-dicarboxylate (6.90 ml, 50 mmol) was dissolved in dichloromethane (100 mL) and cooled to −78° C. DIBAL (1.0 M in DCM, 100 ml, 100 mmol) was added slowly over a period of 30 minutes. The reaction mixture was stirred for 6.5 hours at −78° C. then treated carefully with an aqueous saturated solution of ammonium chloride (16 mL) followed by HCl (1.0 M, 20 mL). The reaction was allowed to warm to room temperature over the weekend. The solids were filtered off and washed with DCM. The filtrate was washed with brine, dried over magnesium sulfate and the solvent removed under reduced pressure (200 mbar at rt). The crude product was purified on silica gel by flash column chromatography to afford the desired compound as a 45% w/w solution in EtOAc/DCM/ether as judged by 1H NMR (3.295 g).
Wird geladen…
