acid derivatives with high (Z)-selectivity in good yields. Moreover, ethyl (4S)- and (4R)-2-(N-Boc-amino)-4,5-isopropylidenedioxy-2-pentenoates prepared by the present method were converted to (2S, 4S)- and (2R, 4R)-4-hydroxyprolines, respectively.
在
三丁基膦和碱的存在下,N-Boc-和NZ-α-
甲苯磺酰基甘
氨酸
乙酯与各种醛反应,以良好的产率提供相应的α,β-二脱氢
氨基酸衍
生物,具有高(Z)选择性。此外,通过本方法制备的(4S)-和(4R)-2-(N-Boc-
氨基)-4,5-异亚丙基二氧基-
2-戊烯酸乙酯转化为(2S, 4S)-和(2R, 4R) )-
4-羟脯
氨酸,分别。