反应详情

To a mixture of N-benzyloxycarbonyl-4-hydroxypiperidine (2.4 g, preparation described by Alig, L. et al (1992), J. Med. Chem. 35, 4393), dirhodium tetraacetate (40 mg) and dichloromethane (15 ml) under argon was added dropwise over 3-4 hours, with stirring, a solution of ethyl diazoacetate (1.2 ml) in dichloromethane (2.5 ml). On completion of the addition, the reaction mixture was stirred at ambient temperature overnight and then evaporated. The resultant oily residue was purified by column chromatography on silica eluting with 30% ethyl acetate/hexane to give ethyl N-(benzyloxycarbonyl)piperidin-4-yloxyacetate (2.4 g) as a colourless oil: NMR Spectrum (CDCl3) 1.20 (3H, t), 1.40 (2H, m), 1.82 (2H, m), 3.13 (2H, m), 3.57 (1H, m), 3.70 (2H, m), 4.11 (2H, q), 4.13 (2H, s), 5.07 (2H, s), 7.35 (5H, m); Mass Spectrum m/Z 322 (M+H)+.

1. additionwas added dropwise over 3-4 hours
2. additionOn completion of the addition
3. stirringthe reaction mixture was stirred at ambient temperature overnight
4. customevaporated
5. customThe resultant oily residue was purified by column chromatography on silica eluting with 30% ethyl acetate/hexane