Stereoselective Synthesis of Polysubstituted Cyclopropanes from Poly(ethylene glycol)Supported Pyrid

Polysubstituted cyclopropanes were efficiently prepared with poly(ethylene glycol)(PEG)as soluble support.The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile(R=CN)or ethyl arylidenecyanoacetate(R=COOEt)in the presence of triethylamine(TEA)afforded PEG-supported cyclopropanecarboxylates,which were cleaved by 1％ KCN/EtOH to obtain polysubstituted cyclopropanes with exclusive trans-selectivity and good yields.