Aldol-additions t0eα- and β-alkoxy aldehydes: The effect of chelation on simple diastereoselectivity
作者:M.T. Reetz、K. Kesseler、A. Jung
DOI:10.1016/s0040-4020(01)98807-6
日期:——
reaction of enol silanes with chiralα- and β-alkoxyaldehydes constitutes the only presently known, general way to perform aldol additions with chelation-control (asymmetric induction 90%). If the enol silane is prochiral, the additional stereoselection (simple diastereoselectivity) is surprisingly good. This unusual effect has been traced to syn-type of complexation of the aldehyde function.
Synthesis of Propionate Motifs: Diastereoselective Tandem Reactions Involving Anionic and Free Radical Based Processes
作者:Yvan Guindon、Karine Houde、Michel Prévost、Benoit Cardinal-David、Serge R. Landry、Benoit Daoust、Mohammed Bencheqroun、Brigitte Guérin
DOI:10.1021/ja010805m
日期:2001.9.1
employing a Mukaiyama reaction in tandem with a hydrogen transfer reaction for the elaboration of propionate motifs. The nature of the protecting groups on the chiral β-alkoxy aldehyde and the type of Lewis acid used are varied to modulate the stereochemical outcome of the tandemreactions. The mode of complexation is thus controlled (monodentate or chelate) for the Mukaiyama reaction to give access to