The stereoselective synthesis of diethyl (S)- or (R)-α-[(O-pivaloyl-hexapyranosyl) amino]benzylphosphonates is achieved via Lewis acid catalyzed addition of diethyl phosphite to O-pivaloylated N-benzylidene -β-D-galactosylamine or N-benzylidene-α-D-arabinopyranosylamine. The process can also be performed by a one-pot procedure selectively giving (S)-aminophosphonic acid derivatives from galactosylamine and (R)-aminophosphonic acid derivatives from β-L-fucosylamine as the chiral auxiliaries.
通过
路易斯酸催化
亚磷酸二乙酯与 O-新戊酰化 N-亚
苄基-δ-
D-半乳糖胺或 N-亚
苄基-δ-
D-阿拉伯吡喃糖基胺的加成,可立体选择性合成(S)-或(R)-δ-[(O-新戊酰-六
吡喃糖基)
氨基]
苄基膦酸二乙酯。 该过程也可以通过单锅程序进行,选择性地从半
乳糖胺中得到(S)-
氨基膦酸衍
生物,从δ²-
L-岩藻糖胺中得到(R)-
氨基膦酸衍
生物作为手性助剂。