Synthetic studies on homophymine A: stereoselective synthesis of (2R,3R,4R,6R)-3-hydroxy-2,4,6-trimethyloctanoic acid
作者:Filomena Bellotta、Maria Valeria D'Auria、Valentina Sepe、Angela Zampella
DOI:10.1016/j.tet.2009.02.069
日期:2009.5
highly stereocontrolled synthesis of (2R,3R,4R,6R)-3-hydroxy-2,4,6-trimethyloctanoic acid, the β-hydroxy acid unit that acylates the N-terminus of homophymine A, has been devised starting from iodoethane and (S,S)-pseudoephedrine propionamide in 9 steps and 36% average overall yield. Comparison of the 1H and 13C NMR and optical rotation data of the resulting β-hydroxy acid with the natural fragment
(2 R,3 R,4 R,6 R)-3-羟基-2,4,6-三甲基辛酸的高效且高度立体控制的合成,该酸将高草甘膦A的N末端酰化,从碘乙烷和(S,S)-伪麻黄碱丙酰胺开始设计9个步骤,平均总收率36%。所得β-羟基酸与天然片段的1 H和13 C NMR和旋光数据的比较明确验证了构型分配为(2 R,3 R,4 R,6 R)。