Asymmetric total synthesis of epolactaene. Part 1: Construction of epoxy-γ-lactam moiety and deduction of absolute stereochemistry
作者:Shinji Marumoto、Hiroshi Kogen、Shunji Naruto
DOI:10.1016/s0040-4020(99)00367-1
日期:1999.6
Enantioselective construction of the epoxy-γ-lactam moiety of epolactaene (1) was completed in 11 steps from (R)-lactaldehyde derivatives. Key steps include: (i) the stereoselective aldol reaction between (R)-lactaldehyde and malonate ester; (ii) diastereospecific lactonization of malonate ester derivative 10; (iii) cyclization of 16 to epoxy-γ-lactam derivative 2. Both enantiomers, (R,R)-2 and (S
从(R)-丙醛衍生物经11个步骤完成环氧乙烷(1)的环氧-γ-内酰胺部分的对映选择性构建。关键步骤包括:(i)(R)-丙醛与丙二酸酯之间的立体选择性羟醛反应;(ii)丙二酸酯衍生物10的非对映特异性内酯化;(iii)将16环化为环氧-γ-内酰胺衍生物2。合成了两种对映体(R,R)-2和(S,S)-2 ,并将它们的旋光度与(+)-上二十碳烯(1)的旋光度进行了比较。结果表明1的绝对构型为(13 R,14 R)。