Efficient Synthesis of Spirocyclic Nucleosides via Michael Addition-Initiated Intermolecular Cyclopropanation Reaction

Abstract

An efficient route to synthesize 2'-spiro[2-oxocyclopentyl]cyclopropyl nucleoside analogues via KO t Bu promoted Michael addition-initiated cyclopropanation reactions of α-thymine acrylates with α-chloro-cycloalkanones has been developed. A wide range of C(2′)-spirocyclic modified nucleoside analogues were obtained with excellent diastereoselectivities (＞ 20∶1) and good yields (up to 85%).