反应详情

N-CBZ-L-serine methyl ester (3.15 g) was dissolved in 40 ml of dichloromethane at 0° C. under argon. Methylenecyclopentane (20 ml) was added, followed by 16 drops of concentrated sulfuric acid. The contents of the vessel were stirred at room temperature overnight then poured into dilute aqueous sodium hydrogen carbonate and extracted with chlorofrom (2×30 ml). The organic layer was dried over sodium sulfate and evaporated. The residual oil was chromatographed on silica gel with 50/50 petroleum ether/diethyl ether to give an oil (78% yield). The product, N-CBZ-O-(1-methylycyclopentyl)-L-serine methyl ester, was confirmed by NMR spectroscopy.

1. extractionextracted with chlorofrom (2×30 ml)
2. dry with materialThe organic layer was dried over sodium sulfate
3. customevaporated
4. customThe residual oil was chromatographed on silica gel with 50/50 petroleum ether/diethyl ether