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

✍ Scribed by Hartmut Ahrens; Mario Paetow; Dieter Hoppe

• Publisher: Elsevier Science
• Year: 1992
• Tongue: French
• Weight: 194 KB
• Volume: 33
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)79084-8

✦ Synopsis

The deprotonation of a dicarbamate, derived from (S)-butane-13-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.