反应详情

Analogously to Example 21 D) 1)c), 2.0 g (6.55 mmol) of 5(S)-[1(S)-(Boc-amino)-2-phenylethyl]-dihydrofuran-2-(3H)-one [Example 21 D) 1)b)] dissolved in 40 ml of THF are deprotonated at -75° C. with 13.1 ml of lithium bis(trimethylsilyl)amide 1M in THF and alkylated (60 min -60° C.) with 1.4 g (7.2 mmol) of 3-bromomethylbenzonitrile (Fluka; Buchs/Switzerland). Column chromatography (SiO2, hexane/ethyl acetate 2:1) and stirring in hexane yields the pure title compound: TLC Rf (D)=0.41; tRet (I)=16.1 min.