反应详情

1.125 g (7.4 mmol) of 1,5-diazabicyclo[5.4.0]undec-5-ene are added at 0° to a solution of 118 g (3 mmol) of N-benzyl-N-tert.-butylsulphonylmethyl-2-(S)-bromo-3-hydroxypropionic acid amide (see Example 4) in 15 ml of absolute tetrahydrofuran and the whole is stirred for a further 90 minutes at room temperature. After working up with methylene chloride and phosphate buffer having a pH of 7.0, the crude product obtained from the organic phase is chromatographed over 50 g of silica gel. After eluting with a mixture of ethyl acetate/toluene (1:1), the pure title compound, identical to the compound according to Example 6, is obtained.