A Convenient Method for Preparation of α-Imino Carboxylic Acid Derivatives and Application to the Asymmetric Synthesis of Unnatural α-Amino Acid Derivative
glycine derivatives for the synthesis of α-imino carboxylic acidderivatives. Using this methodology, utilization of unstable glyoxic acidderivatives was avoided. Furthermore, using this methodology we synthesized novel α-imino carboxylic acidderivatives such as α-imino phenyl ester, perfluoroalkyl etsers, imides, and thioester. The asymmetric Mannich reaction of those novel imine derivatives with 1
Small rings through large templates: A two‐point binding of the substrate radicals to cationic titanocene templates is essential for the success of otherwise impossible 4‐exo cyclizations (see scheme; Bn=benzyl). The cyclobutanes are obtained in high stereoselectivity and can be additionally functionalized in a straightforward manner.
Application of Enantioselective Radical Reactions: Synthesis of (+)-Ricciocarpins A and B
作者:Mukund P. Sibi、Liwen He
DOI:10.1021/ol0495772
日期:2004.5.1
Enantioselective synthesis of (+)-ricciocarpins A and B has been achieved in 41 and 45% overall yields, respectively, starting from a beta-substituted oxazolidinone. The key steps in the strategy are an enantioselective conjugate radical addition and the addition of a furyl organometallic to a key aldehyde intermediate.