反应详情

温度

0 °C

2.47 g (6.0 mmol) of 5(S)-[1(S)-(Boc-amino)-2-(p-benzyloxyphenyl)ethyl]dihydrofuran-2-(3H)-one dissolved in 12 ml of THF and 1.2 ml of 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone are treated, at -70° C. and under a protective gas, with 11.73 ml of a 1M solution of lithium bis(trimethylsilyl)amide in THF, and this mixture is stirred for 15 min; it is then alkylated with 1.946 g (6.0 mmol) of p-benzyloxybenzyl iodide (Example 1d)) in 3 ml of THF (60 min). For hydrolysing, 2.23 ml of propionic acid and 2.23 ml of water are added and the mixture is warmed to 0° C. The reaction mixture is poured onto 30 ml of 10% citric acid solution, and this mixture is extracted twice with ethyl acetate; the organic phases are washed twice with saturated NaHCO3 solution and, finally, with saline. Drying the organic phases with Na2SO4 and evaporating them, and column chromatography (SiO2, hexane/ethyl acetate 4:1) of the residue, and subsequent crystallization from ethyl acetate/hexane, affords the pure title compound: TLC Rf (D)=0.45; tRet (I)=19.9 min; FAB-MS (M+H)+ =608.

1. extractionthis mixture is extracted twice with ethyl acetate
2. washthe organic phases are washed twice with saturated NaHCO3 solution
3. dry with materialDrying the organic phases with Na2SO4
4. customevaporating
5. customthem, and column chromatography (SiO2, hexane/ethyl acetate 4:1) of the residue, and subsequent crystallization from ethyl acetate/hexane