Stereoselective Synthesis of trans-(2R,3S)- and cis-(2R,3R)-Disubstituted Pyrrolidines

to constitute major frameworks of alkaloids, which display diverse and potent biological activities.1 Numerous strate-gies for the synthesis of pyrrolidines have been developed including 1,3-dipolar cycloaddition with azomethine ylide,2 nucleophilic opening of aziridine,3 internal displacement in aminocarbohydrate,4 intramolecular cyclization involving radical,5 acylnitrilium ion,6 β-oxo ester7 and organometallic complex.8 Synthesis of 2,3-disubstituted pyrrolidines attracts much interest because they carry a basic nitrogen atom and a diol that potentially allow extension of the side chain or ring closure. We wish to report herein that trans-(2R,3S)- and cis-(2R,3R)-disubstituted pyrrolidines could be efficiently syn-thesized from D-serine by use of an appropriate coupling reagent. trans-(2R,3S)-Disubstituted pyrrolidine was prepared a