作者:Johan Legters、Erik van Dienst、Lambertus Thijs、Binne Zwanenburg
DOI:10.1002/recl.19921110202
日期:——
prepared from the corresponding 3-aryl-oxirane-2-carboxylic esters by ring opening with sodium azide, were reduced with tin(II) chloride dihydrate in methanol to give 3-amino-3-aryl-2-hydroxypropanoic esters in good yields. Under these conditions, halogen substituents in the aromatic rings were not affected. The nitro group, however, was partially reduced to the amino group. Treatment of aliphatic oxirane-2-carboxylic
由相应的3-芳基-环氧乙烷-2-羧酸酯与叠氮化钠开环制备的3-芳基-3-叠氮基-2-羟基丙酸酯,在甲醇中用氯化锡(II)二水合物还原,得到3-氨基-3-芳基-2-羟基丙酸酯产率高。在这些条件下,芳环中的卤素取代基不受影响。然而,硝基部分还原为氨基。在三氟化硼醚化物的存在下用乙腈处理脂肪族环氧乙烷-2-羧酸酯会导致区域特异性形成2,4-二烷基-2-恶唑啉-5-羧酸酯,这是由于腈在C3处的反应所致。这些恶唑啉-5-羧酸酯的酸性水解得到相应的3-(酰基氨基)-2-羟基羧酸酯。通过这两种互补的方法,