天然海洋环酯肽Stereocalpin A中间体的合成

Synthesis of a Segment of Natural Cyclic Depsipeptide Stereocalpin A

以D-苯丙氨酸为原料,经过硼氢化钠/碘还原后与三光气在碱性条件下环合得到Evans手性助剂(R)-4-苄基-2-噁唑烷酮(2),然后将其与丙酰氯缩合,经过LDA偶联、反式Aldol等反应,合成了天然环酯肽StereocalpinA中含有的独特结构片段,该片段对3种人实体瘤细胞系(HT-29,B16/F10,HepG2)具有中等细胞毒性,总收率为30.6%。结果表明,合成路线简便可行,反应产率高,立体选择性好。是制备该化合物的有效途径。

（R）-4-Benzyl-2-oxazolidinone, an Evans chiral auxiliary reagent, was synthesized from D- phenylalanine as a starting material, which was reduced by sodium borohydride/iodine followed by reacting with bis （ trichloromethyl ） carbonate under alkaline condition. Then the （R） -4-benzyl-2-oxazolidinone was condensated with propionyl chloride and coupled with lithium diisopropylamide （LDA）. After the anti-Aldol reaction, a unique segment of Stereocalpin A was obtained in an overall yield of 30. 6% which has moderate cytotoxicity against three human solid tumor cell lines（ HT-29, B16/F10, HepG2）. The developed method is efficient to synthesize this compound with high yield and selectivity.