Synthesis of novel 3′-C-methyl-4′-thio apionucleosides via highly enantioselective elaboration of quaternary carbon by [3,3]-sigmatropic rearrangement
作者:Joon H. Hong、Mu-Yun Gao、Chung K. Chu
DOI:10.1016/s0040-4039(98)02324-7
日期:1999.1
Asymmetric synthesis of 3′-C-methyl-4′-thio apionucleosides was accomplished from the chiral intermediate 6. The chirality of quaternary carbon of the key intermediate 6 was transferred from the chirality of secondary allylic alcohol 5via [3,3]-sigmatropic Claisen rearrangement with high enantiomeric excess (estimated to be 98.5% ee). The thioglycosyl intermediate 11 was condensed with silylated N4-benzoylcytosine
3' - C-甲基-4'-硫代apionucleosides的不对称合成是由手性中间体6完成的。关键中间体6的季碳的手性通过具有高对映体过量(估计为98.5%ee)的[3,3]-σ克莱森重排从仲烯丙基醇5的手性转移而来。硫代糖基中间体11与甲硅烷基化的N 4-苯甲酰基胞嘧啶缩合,然后脱保护得到所需的核苷12。