An Efficient Asymmetric Construction of Novel Spiro-Fused 2-Oxindoles/α-Methy-paraconic Ester

作者：Guo, Yanjun; Meng, Chenhong; Liu, Xueli; Xu, Danqian; Xia, Aibao^*

来源：Chinese Journal of Organic Chemistry, 2017, 37(10): 2776-2782.

DOI：10.6023/cjoc201703013

• asymmetric synthesis
• spirooxindole gamma-lactones
• paraconic acids

Chiral spirooxindole gamma-lactones with three stereogenic centres are rare. An efficient asymmetric construction of novel spiro-fused 2-oxindole/alpha-methy-paraconnic ester is reported, which was offered via organocatalytic Michael reaction of propaldehyde and olefinic oxindoles, with subsequent H2O2/K2CO3 system-mediated alpha-hydroxylation/hemiacetalization cascade reaction under oil/water two-phase conditions, and final oxidative gamma-lactonization by pyridinium chlorochromate (PCC). The presented strategy features mild reaction conditions, excellent yields (91%similar to 98%) and enatioselectiveties (87%similar to 95%), and accordingly constitutes a facile and new method for the synthesis of chiral multisubstituted spirooxindole gamma-lactones. All structures of new products were confirmed by H-1 NMR, C-13 NMR and HRMS techniques.

• 出版日期2017-10-25
• 单位浙江工业大学