Selective synthesis of optically active 3-haloazetidin-2-ones or aziridines by the condensation of various metal enolates of α-haloacetate with a chiral imine

Article abstract of DOI:10.1016/S0040-4039(00)74774-5

Reaction products and their diastereofacial selectivity in the condensation of the ester enolates of α-haloacetate with a chiral imine possessing 1,3-dioxolane ring derived from (2S,3S)-1,4-dimethoxy-2,3-butanediol as a chiral auxiliary can be fully controlled by the metal enolate used; i.e., (3R,4R)-3-haloazetidine-2-one is obtained stereoselectively by the use of the triisopropoxytitanium enolates, while condensation with the lithium or zinc enolates provides (2R,3S)- or (2S,3R)-aziridine, respectively.