名称:
                                Stereoselective generation of 1,3- and 1,4-dioxy-substituted carbanions by sparteine-assisted deprotonation of chiral precursors: Substrate or reagent control in the synthesis of α,γ- and α,δ-diols
                             
                            
                                摘要:
                                The deprotonation of a dicarbamate, derived from (S)-butane-1,3-diol, by sec-butyllithium takes an highly diastereoselective, but opposite, direction in the presence of (-)-sparteine and of tetramethylethylenediamine (TMEDA), respectively. The (S)-pentane-1,4-diol derivative shows the same stereochemical preference under both conditions.