A Novel Class of Conformationally Constrained, Masked Cysteines: Synthesis of 2-Alkyl- and 2-Arylsulfanyl-1-aminocyclopropanecarboxylic Acids
作者:F. Clerici、M. L. Gelmi、D. Pocar
DOI:10.1021/jo9810011
日期:1999.2.1
4-(chloromethylene)oxazolone 1 and mercaptans 2. Oxazolones 3 were used as starting materials for the preparation of unknown 2-sulfanyl-1-aminocyclopropanecarboxylic acid derivatives 5 and7. Oxazolones 3 were cyclopropanated at the exocyclic double bond with diazomethane, giving a mixture of the two (Z)- and (E)-spirocyclopropane oxazolones 4 with good diastereoselectivity. These were then treated with
从4-(氯亚甲基)恶唑酮1和硫醇2开始实现了4-硫烷基亚甲基-5(4H)-恶唑酮3的方便合成。恶唑酮3被用作制备未知的2-硫烷基-1-氨基环丙烷羧酸的起始原料导数5和7。恶唑酮3在环外双键处与重氮甲烷环丙烷化,得到具有良好非对映选择性的两种(Z)-和(E)-螺环丙烷恶唑酮4的混合物。然后将它们用乙醇和DMAP处理以产生相应的羧酸盐5。使用碘在乙醇溶液中的溶液,将三苯甲基衍生物5d转化为非对映异构体二硫化物6的混合物。二硫化物6是用于制备3-硫烷基取代的2,3-甲基氨基酸7的便利合成子。